Merge branch 'query-refactor'

24 files changed, 1526 insertions, 1935 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2c16006..d0e14c1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,9 +29,9 @@ if (tests)
     set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/bin/tests")
     file(MAKE_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/tests/data")
 
-    add_executable(wirs_tests ${CMAKE_CURRENT_SOURCE_DIR}/tests/wirs_tests.cpp)
-    target_link_libraries(wirs_tests PUBLIC gsl check subunit pthread)
-    target_include_directories(wirs_tests PRIVATE include external/psudb-common/cpp/include)
+    add_executable(augbtree_tests ${CMAKE_CURRENT_SOURCE_DIR}/tests/augbtree_tests.cpp)
+    target_link_libraries(augbtree_tests PUBLIC gsl check subunit pthread)
+    target_include_directories(augbtree_tests PRIVATE include external/psudb-common/cpp/include)
 
     add_executable(internal_level_tests ${CMAKE_CURRENT_SOURCE_DIR}/tests/internal_level_tests.cpp)
     target_link_libraries(internal_level_tests PUBLIC gsl check subunit pthread)
@@ -45,10 +45,6 @@ if (tests)
     target_link_libraries(vptree_tests PUBLIC gsl check subunit pthread)
     target_include_directories(vptree_tests PRIVATE include external/vptree external/psudb-common/cpp/include)
 
-    #add_executable(dynamic_extension_tests ${CMAKE_CURRENT_SOURCE_DIR}/tests/dynamic_extension_tests.cpp)
-    #target_link_libraries(dynamic_extension_tests PUBLIC gsl check subunit pthread)
-    #target_include_directories(dynamic_extension_tests PRIVATE include)
-
     add_executable(de_tier_tag ${CMAKE_CURRENT_SOURCE_DIR}/tests/de_tier_tag.cpp)
     target_link_libraries(de_tier_tag PUBLIC gsl check subunit pthread)
     target_include_directories(de_tier_tag PRIVATE include external/psudb-common/cpp/include external)
@@ -69,9 +65,9 @@ if (tests)
     target_link_libraries(memisam_tests PUBLIC gsl check subunit pthread)
     target_include_directories(memisam_tests PRIVATE include external/psudb-common/cpp/include)
 
-    add_executable(wss_tests ${CMAKE_CURRENT_SOURCE_DIR}/tests/wss_tests.cpp)
-    target_link_libraries(wss_tests PUBLIC gsl check subunit pthread)
-    target_include_directories(wss_tests PRIVATE include external/psudb-common/cpp/include)
+    add_executable(alias_tests ${CMAKE_CURRENT_SOURCE_DIR}/tests/alias_tests.cpp)
+    target_link_libraries(alias_tests PUBLIC gsl check subunit pthread)
+    target_include_directories(alias_tests PRIVATE include external/psudb-common/cpp/include)
 
     add_executable(triespline_tests ${CMAKE_CURRENT_SOURCE_DIR}/tests/triespline_tests.cpp)
     target_link_libraries(triespline_tests PUBLIC gsl check subunit pthread)
diff --git a/include/framework/QueryRequirements.h b/include/framework/QueryRequirements.h
new file mode 100644
index 0000000..ff4eaff
--- /dev/null
+++ b/include/framework/QueryRequirements.h
@@ -0,0 +1,17 @@
+/*
+ * include/framework/QueryRequirements.h
+ *
+ * Copyright (C) 2023 Douglas B. Rumbaugh <drumbaugh@psu.edu> 
+ *
+ * All rights reserved. Published under the Modified BSD License.
+ *
+ * A header file containing the necessary includes for Shard
+ * development.
+ *
+ */
+#pragma once
+
+#include "framework/structure/MutableBuffer.h"
+#include "framework/interface/Record.h"
+#include "framework/interface/Shard.h"
+#include "framework/interface/Query.h"
diff --git a/include/framework/interface/Shard.h b/include/framework/interface/Shard.h
index d3a6cf8..92cdca0 100644
--- a/include/framework/interface/Shard.h
+++ b/include/framework/interface/Shard.h
@@ -33,4 +33,10 @@ concept ShardInterface = requires(S s, S **spp, void *p, bool b, size_t i) {
     {s.get_aux_memory_usage()} -> std::convertible_to<size_t>;
 };
 
+template <typename S, typename R>
+concept SortedShardInterface = ShardInterface<S> && requires(S s, R r, R *rp) {
+    {s.lower_bound(r)} -> std::convertible_to<size_t>;
+    {s.upper_bound(r)} -> std::convertible_to<size_t>;
+};
+
 }
diff --git a/include/query/irs.h b/include/query/irs.h
new file mode 100644
index 0000000..4cb69b0
--- /dev/null
+++ b/include/query/irs.h
@@ -0,0 +1,216 @@
+/*
+ * include/query/irs.h
+ *
+ * Copyright (C) 2023 Douglas B. Rumbaugh <drumbaugh@psu.edu> 
+ *
+ * All rights reserved. Published under the Modified BSD License.
+ *
+ */
+#pragma once
+
+#include "framework/QueryRequirements.h"
+
+namespace de { namespace irs {
+
+template <RecordInterface R>
+struct Parms {
+    decltype(R::key) lower_bound;
+    decltype(R::key) upper_bound;
+    size_t sample_size;
+    gsl_rng *rng;
+};
+
+
+template <RecordInterface R>
+struct State {
+    size_t lower_bound;
+    size_t upper_bound;
+    size_t sample_size;
+    size_t total_weight;
+};
+
+template <RecordInterface R>
+struct BufferState {
+    size_t cutoff;
+    std::vector<Wrapped<R>> records;
+    size_t sample_size;
+};
+
+template <ShardInterface S, RecordInterface R, bool Rejection=true>
+class Query {
+public:
+    constexpr static bool EARLY_ABORT=false;
+    constexpr static bool SKIP_DELETE_FILTER=false;
+
+    static void *get_query_state(S *shard, void *parms) {
+        auto res = new State<R>();
+        decltype(R::key) lower_key = ((Parms<R> *) parms)->lower_bound;
+        decltype(R::key) upper_key = ((Parms<R> *) parms)->upper_bound;
+
+        res->lower_bound = shard->get_lower_bound(lower_key);
+        res->upper_bound = shard->get_upper_bound(upper_key);
+
+        if (res->lower_bound == shard->get_record_count()) {
+            res->total_weight = 0;
+        } else {
+            res->total_weight = res->upper_bound - res->lower_bound;
+        }
+
+        res->sample_size = 0;
+        return res;
+    }
+
+    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
+        auto res = new BufferState<R>();
+
+        res->cutoff = buffer->get_record_count();
+        res->sample_size = 0;
+
+        if constexpr (Rejection) {
+            return res;
+        }
+
+        auto lower_key = ((Parms<R> *) parms)->lower_bound;
+        auto upper_key = ((Parms<R> *) parms)->upper_bound;
+
+        for (size_t i=0; i<res->cutoff; i++) {
+            if (((buffer->get_data() + i)->rec.key >= lower_key) && ((buffer->get_data() + i)->rec.key <= upper_key)) { 
+                res->records.emplace_back(*(buffer->get_data() + i));
+            }
+        }
+
+        return res;
+    }
+
+    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, void *buff_state) {
+        auto p = (Parms<R> *) query_parms;
+        auto bs = (buff_state) ? (BufferState<R> *) buff_state : nullptr;
+
+        std::vector<size_t> shard_sample_sizes(shard_states.size()+1, 0);
+        size_t buffer_sz = 0;
+
+        std::vector<size_t> weights;
+        if constexpr (Rejection) {
+            weights.push_back((bs) ? bs->cutoff : 0);
+        } else {
+            weights.push_back((bs) ? bs->records.size() : 0);
+        }
+
+        size_t total_weight = 0;
+        for (auto &s : shard_states) {
+            auto state = (State<R> *) s;
+            total_weight += state->total_weight;
+            weights.push_back(state->total_weight);
+        }
+
+        // if no valid records fall within the query range, just
+        // set all of the sample sizes to 0 and bail out.
+        if (total_weight == 0) {
+            for (size_t i=0; i<shard_states.size(); i++) {
+                auto state = (State<R> *) shard_states[i];
+                state->sample_size = 0;
+            }
+
+            return;
+        }
+
+        std::vector<double> normalized_weights;
+        for (auto w : weights) {
+            normalized_weights.push_back((double) w / (double) total_weight);
+        }
+
+        auto shard_alias = psudb::Alias(normalized_weights);
+        for (size_t i=0; i<p->sample_size; i++) {
+            auto idx = shard_alias.get(p->rng);            
+            if (idx == 0) {
+                buffer_sz++;
+            } else {
+                shard_sample_sizes[idx - 1]++;
+            }
+        }
+
+        if (bs) {
+            bs->sample_size = buffer_sz;
+        }
+        for (size_t i=0; i<shard_states.size(); i++) {
+            auto state = (State<R> *) shard_states[i];
+            state->sample_size = shard_sample_sizes[i+1];
+        }
+    }
+
+    static std::vector<Wrapped<R>> query(S *shard, void *q_state, void *parms) { 
+        auto lower_key = ((Parms<R> *) parms)->lower_bound;
+        auto upper_key = ((Parms<R> *) parms)->upper_bound;
+        auto rng = ((Parms<R> *) parms)->rng;
+
+        auto state = (State<R> *) q_state;
+        auto sample_sz = state->sample_size;
+
+        std::vector<Wrapped<R>> result_set;
+
+        if (sample_sz == 0 || state->lower_bound == shard->get_record_count()) {
+            return result_set;
+        }
+
+        size_t attempts = 0;
+        size_t range_length = state->upper_bound - state->lower_bound;
+        do {
+            attempts++;
+            size_t idx = (range_length > 0) ? gsl_rng_uniform_int(rng, range_length) : 0;
+            result_set.emplace_back(*shard->get_record_at(state->lower_bound + idx));
+        } while (attempts < sample_sz);
+
+        return result_set;
+    }
+
+    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
+        auto st = (BufferState<R> *) state;
+        auto p = (Parms<R> *) parms;
+
+        std::vector<Wrapped<R>> result;
+        result.reserve(st->sample_size);
+
+        if constexpr (Rejection) {
+            for (size_t i=0; i<st->sample_size; i++) {
+                auto idx = gsl_rng_uniform_int(p->rng, st->cutoff);
+                auto rec = buffer->get_data() + idx;
+
+                if (rec->rec.key >= p->lower_bound && rec->rec.key <= p->upper_bound) {
+                    result.emplace_back(*rec);
+                }
+            }
+
+            return result;
+        }
+
+        for (size_t i=0; i<st->sample_size; i++) {
+            auto idx = gsl_rng_uniform_int(p->rng, st->records.size());
+            result.emplace_back(st->records[idx]);
+        }
+
+        return result;
+    }
+
+    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
+        std::vector<R> output;
+
+        for (size_t i=0; i<results.size(); i++) {
+            for (size_t j=0; j<results[i].size(); j++) {
+                output.emplace_back(results[i][j].rec);
+            }
+        }
+
+        return output;
+    }
+
+    static void delete_query_state(void *state) {
+        auto s = (State<R> *) state;
+        delete s;
+    }
+
+    static void delete_buffer_query_state(void *state) {
+        auto s = (BufferState<R> *) state;
+        delete s;
+    }
+};
+}}
diff --git a/include/query/rangequery.h b/include/query/rangequery.h
new file mode 100644
index 0000000..b9ac9db
--- /dev/null
+++ b/include/query/rangequery.h
@@ -0,0 +1,167 @@
+/*
+ * include/query/rangequery.h
+ *
+ * Copyright (C) 2023 Douglas B. Rumbaugh <drumbaugh@psu.edu> 
+ *
+ * All rights reserved. Published under the Modified BSD License.
+ *
+ */
+#pragma once
+
+#include "framework/interface/Record.h"
+#include "framework/interface/Shard.h"
+#include "framework/structure/MutableBuffer.h"
+#include "psu-ds/PriorityQueue.h"
+#include "util/Cursor.h"
+
+namespace de { namespace rq {
+
+template <RecordInterface R>
+struct Parms {
+    decltype(R::key) lower_bound;
+    decltype(R::key) upper_bound;
+};
+
+template <RecordInterface R>
+struct State {
+    size_t start_idx;
+    size_t stop_idx;
+};
+
+template <RecordInterface R>
+struct BufferState {
+    size_t cutoff;
+};
+
+template <ShardInterface S, RecordInterface R>
+class Query {
+public:
+    constexpr static bool EARLY_ABORT=false;
+    constexpr static bool SKIP_DELETE_FILTER=true;
+
+    static void *get_query_state(S *shard, void *parms) {
+        auto res = new State<R>();
+        auto p = (Parms<R> *) parms;
+
+        res->start_idx = shard->get_lower_bound(p->lower_bound);
+        res->stop_idx = shard->get_record_count();
+
+        return res;
+    }
+
+    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
+        auto res = new BufferState<R>();
+        res->cutoff = buffer->get_record_count();
+
+        return res;
+    }
+
+    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, std::vector<void*> &buffer_states) {
+        return;
+    }
+
+    static std::vector<Wrapped<R>> query(S *shard, void *q_state, void *parms) {
+        std::vector<Wrapped<R>> records;
+        auto p = (Parms<R> *) parms;
+        auto s = (State<R> *) q_state;
+
+        // if the returned index is one past the end of the
+        // records for the PGM, then there are not records
+        // in the index falling into the specified range.
+        if (s->start_idx == shard->get_record_count()) {
+            return records;
+        }
+
+        auto ptr = shard->get_record_at(s->start_idx);
+        
+        // roll the pointer forward to the first record that is
+        // greater than or equal to the lower bound.
+        while(ptr->rec.key < p->lower_bound) {
+            ptr++;
+        }
+
+        while (ptr->rec.key <= p->upper_bound && ptr < shard->get_data() + s->stop_idx) {
+            records.emplace_back(*ptr);
+            ptr++;
+        }
+
+        return records;
+    }
+
+    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
+        auto p = (Parms<R> *) parms;
+        auto s = (BufferState<R> *) state;
+
+        std::vector<Wrapped<R>> records;
+        for (size_t i=0; i<s->cutoff; i++) {
+            auto rec = buffer->get_data() + i;
+            if (rec->rec.key >= p->lower_bound && rec->rec.key <= p->upper_bound) {
+                records.emplace_back(*rec);
+            }
+        }
+
+        return records;
+    }
+
+    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
+        std::vector<Cursor<Wrapped<R>>> cursors;
+        cursors.reserve(results.size());
+
+        psudb::PriorityQueue<Wrapped<R>> pq(results.size());
+        size_t total = 0;
+		size_t tmp_n = results.size();
+        
+
+        for (size_t i = 0; i < tmp_n; ++i)
+			if (results[i].size() > 0){
+	            auto base = results[i].data();
+		        cursors.emplace_back(Cursor{base, base + results[i].size(), 0, results[i].size()});
+				assert(i == cursors.size() - 1);
+			    total += results[i].size();
+				pq.push(cursors[i].ptr, tmp_n - i - 1);
+			} else {
+				cursors.emplace_back(Cursor<Wrapped<R>>{nullptr, nullptr, 0, 0});
+			}
+
+        if (total == 0) {
+            return std::vector<R>();
+        }
+
+        std::vector<R> output;
+        output.reserve(total);
+
+        while (pq.size()) {
+            auto now = pq.peek();
+            auto next = pq.size() > 1 ? pq.peek(1) : psudb::queue_record<Wrapped<R>>{nullptr, 0};
+            if (!now.data->is_tombstone() && next.data != nullptr &&
+                now.data->rec == next.data->rec && next.data->is_tombstone()) {
+                
+                pq.pop(); pq.pop();
+                auto& cursor1 = cursors[tmp_n - now.version - 1];
+                auto& cursor2 = cursors[tmp_n - next.version - 1];
+                if (advance_cursor<Wrapped<R>>(cursor1)) pq.push(cursor1.ptr, now.version);
+                if (advance_cursor<Wrapped<R>>(cursor2)) pq.push(cursor2.ptr, next.version);
+            } else {
+                auto& cursor = cursors[tmp_n - now.version - 1];
+                if (!now.data->is_tombstone()) output.push_back(cursor.ptr->rec);
+                pq.pop();
+                
+                if (advance_cursor<Wrapped<R>>(cursor)) pq.push(cursor.ptr, now.version);
+            }
+        }
+
+        return output;
+    }
+
+    static void delete_query_state(void *state) {
+        auto s = (State<R> *) state;
+        delete s;
+    }
+
+    static void delete_buffer_query_state(void *state) {
+        auto s = (BufferState<R> *) state;
+        delete s;
+    }
+};
+
+}}
diff --git a/include/query/wirs.h b/include/query/wirs.h
new file mode 100644
index 0000000..1113b1d
--- /dev/null
+++ b/include/query/wirs.h
@@ -0,0 +1,240 @@
+/*
+ * include/query/wirs.h
+ *
+ * Copyright (C) 2023 Douglas B. Rumbaugh <drumbaugh@psu.edu> 
+ *
+ * All rights reserved. Published under the Modified BSD License.
+ *
+ */
+#pragma once
+
+#include "framework/interface/Record.h"
+#include "framework/interface/Shard.h"
+#include "framework/structure/MutableBuffer.h"
+#include "psu-ds/Alias.h"
+
+namespace de { namespace wirs {
+
+template <WeightedRecordInterface R>
+struct Parms {
+    decltype(R::key) lower_bound;
+    decltype(R::key) upper_bound;
+    size_t sample_size;
+    gsl_rng *rng;
+};
+
+template <WeightedRecordInterface R>
+struct State {
+    decltype(R::weight) total_weight;
+    std::vector<void*> nodes;
+    psudb::Alias* top_level_alias;
+    size_t sample_size;
+
+    State() {
+        total_weight = 0;
+        top_level_alias = nullptr;
+    }
+
+    ~State() {
+        if (top_level_alias) delete top_level_alias;
+    }
+};
+
+template <RecordInterface R>
+struct BufferState {
+    size_t cutoff;
+    psudb::Alias* alias;
+    std::vector<Wrapped<R>> records;
+    decltype(R::weight) max_weight;
+    size_t sample_size;
+    decltype(R::weight) total_weight;
+
+    ~BufferState() {
+        delete alias;
+    }
+};
+
+template <ShardInterface S, RecordInterface R, bool Rejection=true>
+class Query {
+public:
+    constexpr static bool EARLY_ABORT=false;
+    constexpr static bool SKIP_DELETE_FILTER=false;
+
+    static void *get_query_state(S *shard, void *parms) {
+        auto res = new State<R>();
+        decltype(R::key) lower_key = ((Parms<R> *) parms)->lower_bound;
+        decltype(R::key) upper_key = ((Parms<R> *) parms)->upper_bound;
+
+        std::vector<decltype(R::weight)> weights;
+        res->total_weight = shard->find_covering_nodes(lower_key, upper_key, res->nodes, weights);
+
+        std::vector<double> normalized_weights;
+        for (auto weight : weights) {
+            normalized_weights.emplace_back(weight / res->total_weight);
+        }
+
+        res->top_level_alias = new psudb::Alias(normalized_weights);
+        res->sample_size = 0;
+
+        return res;
+    }
+
+    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
+        BufferState<R> *state = new BufferState<R>();
+        auto parameters = (Parms<R>*) parms;
+
+        if constexpr (Rejection) {
+            state->cutoff = buffer->get_record_count() - 1;
+            state->max_weight = buffer->get_max_weight();
+            state->total_weight = buffer->get_total_weight();
+            state->sample_size = 0;
+            return state;
+        }
+
+        std::vector<decltype(R::weight)> weights;
+
+        state->cutoff = buffer->get_record_count() - 1;
+        decltype(R::weight) total_weight = 0;
+
+        for (size_t i = 0; i <= state->cutoff; i++) {
+            auto rec = buffer->get_data() + i;
+
+            if (rec->rec.key >= parameters->lower_bound && rec->rec.key <= parameters->upper_bound && !rec->is_tombstone() && !rec->is_deleted()) {
+              weights.push_back(rec->rec.weight);
+              state->records.push_back(*rec);
+              total_weight += rec->rec.weight;
+            }
+        }
+
+        std::vector<double> normalized_weights;
+        for (size_t i = 0; i < weights.size(); i++) {
+            normalized_weights.push_back(weights[i] / total_weight);
+        }
+
+        state->total_weight = total_weight;
+        state->alias = new psudb::Alias(normalized_weights);
+        state->sample_size = 0;
+
+        return state;
+    }
+
+    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, std::vector<void*> &buffer_states) {
+        auto p = (Parms<R> *) query_parms;
+
+        std::vector<size_t> shard_sample_sizes(shard_states.size()+buffer_states.size(), 0);
+        size_t buffer_sz = 0;
+
+        std::vector<decltype(R::weight)> weights;
+
+        decltype(R::weight) total_weight = 0;
+        for (auto &s : buffer_states) {
+            auto bs = (BufferState<R> *) s;
+            total_weight += bs->total_weight;
+            weights.push_back(bs->total_weight);
+        }
+
+        for (auto &s : shard_states) {
+            auto state = (State<R> *) s;
+            total_weight += state->total_weight;
+            weights.push_back(state->total_weight);
+        }
+
+        std::vector<double> normalized_weights;
+        for (auto w : weights) {
+            normalized_weights.push_back((double) w / (double) total_weight);
+        }
+
+        auto shard_alias = psudb::Alias(normalized_weights);
+        for (size_t i=0; i<p->sample_size; i++) {
+            auto idx = shard_alias.get(p->rng);            
+
+            if (idx < buffer_states.size()) {
+                auto state = (BufferState<R> *) buffer_states[idx];
+                state->sample_size++;
+            } else {
+                auto state = (State<R> *) shard_states[idx - buffer_states.size()];
+                state->sample_size++;
+            }
+        }
+    }
+
+    static std::vector<Wrapped<R>> query(S *shard, void *q_state, void *parms) {
+        auto lower_key = ((Parms<R> *) parms)->lower_bound;
+        auto upper_key = ((Parms<R> *) parms)->upper_bound;
+        auto rng = ((Parms<R> *) parms)->rng;
+
+        auto state = (State<R> *) q_state;
+        auto sample_size = state->sample_size;
+
+        std::vector<Wrapped<R>> result_set;
+
+        if (sample_size == 0) {
+            return result_set;
+        }
+        size_t cnt = 0;
+        size_t attempts = 0;
+
+        for (size_t i=0; i<sample_size; i++) {
+            auto rec = shard->get_weighted_sample(lower_key, upper_key,
+                                                  state->nodes[state->top_level_alias->get(rng)],
+                                                  rng);
+            if (rec) {
+                result_set.emplace_back(*rec);
+            }
+        }
+
+        return result_set;
+    }
+
+    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
+        auto st = (BufferState<R> *) state;
+        auto p = (Parms<R> *) parms;
+
+        std::vector<Wrapped<R>> result;
+        result.reserve(st->sample_size);
+
+        if constexpr (Rejection) {
+            for (size_t i=0; i<st->sample_size; i++) {
+                auto idx = gsl_rng_uniform_int(p->rng, st->cutoff);
+                auto rec = buffer->get_data() + idx;
+
+                auto test = gsl_rng_uniform(p->rng) * st->max_weight;
+
+                if (test <= rec->rec.weight && rec->rec.key >= p->lower_bound && rec->rec.key <= p->upper_bound) {
+                    result.emplace_back(*rec);
+                }
+            }
+            return result;
+        }
+
+        for (size_t i=0; i<st->sample_size; i++) {
+            auto idx = st->alias->get(p->rng);
+            result.emplace_back(st->records[idx]);
+        }
+
+        return result;
+    }
+
+    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
+        std::vector<R> output;
+
+        for (size_t i=0; i<results.size(); i++) {
+            for (size_t j=0; j<results[i].size(); j++) {
+                output.emplace_back(results[i][j].rec);
+            }
+        }
+
+        return output;
+    }
+
+    static void delete_query_state(void *state) {
+        auto s = (State<R> *) state;
+        delete s;
+    }
+
+    static void delete_buffer_query_state(void *state) {
+        auto s = (BufferState<R> *) state;
+        delete s;
+    }
+};
+}}
diff --git a/include/query/wss.h b/include/query/wss.h
new file mode 100644
index 0000000..794485c
--- /dev/null
+++ b/include/query/wss.h
@@ -0,0 +1,204 @@
+/*
+ * include/query/rangequery.h
+ *
+ * Copyright (C) 2023 Douglas B. Rumbaugh <drumbaugh@psu.edu> 
+ *
+ * All rights reserved. Published under the Modified BSD License.
+ *
+ */
+#pragma once
+
+#include "framework/interface/Record.h"
+#include "framework/interface/Shard.h"
+#include "framework/structure/MutableBuffer.h"
+
+namespace de { namespace wss {
+
+template <WeightedRecordInterface R>
+struct Parms {
+    size_t sample_size;
+    gsl_rng *rng;
+};
+
+template <WeightedRecordInterface R>
+struct State {
+    decltype(R::weight) total_weight;
+    size_t sample_size;
+
+    State() {
+        total_weight = 0;
+    }
+};
+
+template <RecordInterface R>
+struct BufferState {
+    size_t cutoff;
+    size_t sample_size;
+    psudb::Alias *alias;
+    decltype(R::weight) max_weight;
+    decltype(R::weight) total_weight;
+
+    ~BufferState() {
+        delete alias;
+    }
+};
+
+template <ShardInterface S, RecordInterface R, bool Rejection=true>
+class Query {
+public:
+    constexpr static bool EARLY_ABORT=false;
+    constexpr static bool SKIP_DELETE_FILTER=false;
+
+    static void *get_query_state(S *shard, void *parms) {
+        auto res = new State<R>();
+        res->total_weight = shard->get_total_weight();
+        res->sample_size = 0;
+
+        return res;
+    }
+
+    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
+        BufferState<R> *state = new BufferState<R>();
+        auto parameters = (Parms<R>*) parms;
+        if constexpr (Rejection) {
+            state->cutoff = buffer->get_record_count() - 1;
+            state->max_weight = buffer->get_max_weight();
+            state->total_weight = buffer->get_total_weight();
+            return state;
+        }
+
+        std::vector<double> weights;
+
+        state->cutoff = buffer->get_record_count() - 1;
+        double total_weight = 0.0;
+
+        for (size_t i = 0; i <= state->cutoff; i++) {
+            auto rec = buffer->get_data() + i;
+            weights.push_back(rec->rec.weight);
+            total_weight += rec->rec.weight;
+        }
+
+        for (size_t i = 0; i < weights.size(); i++) {
+            weights[i] = weights[i] / total_weight;
+        }
+
+        state->alias = new psudb::Alias(weights);
+        state->total_weight = total_weight;
+
+        return state;
+    }
+
+    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, std::vector<void*> &buffer_states) {
+        auto p = (Parms<R> *) query_parms;
+
+        std::vector<size_t> shard_sample_sizes(shard_states.size()+buffer_states.size(), 0);
+        size_t buffer_sz = 0;
+
+        std::vector<decltype(R::weight)> weights;
+
+        decltype(R::weight) total_weight = 0;
+        for (auto &s : buffer_states) {
+            auto bs = (BufferState<R> *) s;
+            total_weight += bs->total_weight;
+            weights.push_back(bs->total_weight);
+        }
+
+        for (auto &s : shard_states) {
+            auto state = (State<R> *) s;
+            total_weight += state->total_weight;
+            weights.push_back(state->total_weight);
+        }
+
+        std::vector<double> normalized_weights;
+        for (auto w : weights) {
+            normalized_weights.push_back((double) w / (double) total_weight);
+        }
+
+        auto shard_alias = psudb::Alias(normalized_weights);
+        for (size_t i=0; i<p->sample_size; i++) {
+            auto idx = shard_alias.get(p->rng);            
+
+            if (idx < buffer_states.size()) {
+                auto state = (BufferState<R> *) buffer_states[idx];
+                state->sample_size++;
+            } else {
+                auto state = (State<R> *) shard_states[idx - buffer_states.size()];
+                state->sample_size++;
+            }
+        }
+    }
+
+    static std::vector<Wrapped<R>> query(S *shard, void *q_state, void *parms) {
+        auto rng = ((Parms<R> *) parms)->rng;
+
+        auto state = (State<R> *) q_state;
+        auto sample_size = state->sample_size;
+
+        std::vector<Wrapped<R>> result_set;
+
+        if (sample_size == 0) {
+            return result_set;
+        }
+        size_t attempts = 0;
+        do {
+            attempts++;
+            size_t idx = shard->get_weighted_sample(rng);
+            result_set.emplace_back(*shard->get_record_at(idx));
+        } while (attempts < sample_size);
+
+        return result_set;
+    }
+
+    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
+        auto st = (BufferState<R> *) state;
+        auto p = (Parms<R> *) parms;
+
+        std::vector<Wrapped<R>> result;
+        result.reserve(st->sample_size);
+
+        if constexpr (Rejection) {
+            for (size_t i=0; i<st->sample_size; i++) {
+                auto idx = gsl_rng_uniform_int(p->rng, st->cutoff);
+                auto rec = buffer->get_data() + idx;
+
+                auto test = gsl_rng_uniform(p->rng) * st->max_weight;
+
+                if (test <= rec->rec.weight) {
+                    result.emplace_back(*rec);
+                }
+            }
+            return result;
+        }
+
+        for (size_t i=0; i<st->sample_size; i++) {
+            auto idx = st->alias->get(p->rng);
+            result.emplace_back(*(buffer->get_data() + idx));
+        }
+
+        return result;
+    }
+
+    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
+        std::vector<R> output;
+
+        for (size_t i=0; i<results.size(); i++) {
+            for (size_t j=0; j<results[i].size(); j++) {
+                output.emplace_back(results[i][j].rec);
+            }
+        }
+
+        return output;
+    }
+
+    static void delete_query_state(void *state) {
+        auto s = (State<R> *) state;
+        delete s;
+    }
+
+    static void delete_buffer_query_state(void *state) {
+        auto s = (BufferState<R> *) state;
+        delete s;
+    }
+};
+
+}}
diff --git a/include/shard/WSS.h b/include/shard/Alias.h
index 4e3a326..a4a7d02 100644
--- a/include/shard/WSS.h
+++ b/include/shard/Alias.h
@@ -1,5 +1,5 @@
 /*
- * include/shard/WSS.h
+ * include/shard/Alias.h
  *
  * Copyright (C) 2023 Douglas B. Rumbaugh <drumbaugh@psu.edu>
  *                    Dong Xie <dongx@psu.edu>
@@ -9,7 +9,6 @@
  */
 #pragma once
 
-
 #include <vector>
 #include <cassert>
 #include <queue>
@@ -28,59 +27,20 @@ using psudb::CACHELINE_SIZE;
 using psudb::BloomFilter;
 using psudb::PriorityQueue;
 using psudb::queue_record;
-using psudb::Alias;
 
 namespace de {
 
 thread_local size_t wss_cancelations = 0;
 
 template <WeightedRecordInterface R>
-struct wss_query_parms {
-    size_t sample_size;
-    gsl_rng *rng;
-};
-
-template <WeightedRecordInterface R, bool Rejection>
-class WSSQuery;
-
-template <WeightedRecordInterface R>
-struct WSSState {
-    decltype(R::weight) total_weight;
-    size_t sample_size;
-
-    WSSState() {
-        total_weight = 0;
-    }
-};
-
-template <WeightedRecordInterface R>
-struct WSSBufferState {
-    size_t cutoff;
-    size_t sample_size;
-    Alias* alias;
-    decltype(R::weight) max_weight;
-    decltype(R::weight) total_weight;
-
-    ~WSSBufferState() {
-        delete alias;
-    }
-
-};
-
-template <WeightedRecordInterface R>
-class WSS {
+class Alias {
 private:
     typedef decltype(R::key) K;
     typedef decltype(R::value) V;
     typedef decltype(R::weight) W;
 
 public:
-
-    // FIXME: there has to be a better way to do this
-    friend class WSSQuery<R, true>;
-    friend class WSSQuery<R, false>;
-
-    WSS(MutableBuffer<R>* buffer)
+    Alias(MutableBuffer<R>* buffer)
     : m_reccnt(0), m_tombstone_cnt(0), m_total_weight(0), m_alias(nullptr), m_bf(nullptr) {
 
         m_alloc_size = (buffer->get_record_count() * sizeof(Wrapped<R>)) + (CACHELINE_SIZE - (buffer->get_record_count() * sizeof(Wrapped<R>)) % CACHELINE_SIZE);
@@ -132,7 +92,7 @@ public:
         }
     }
 
-    WSS(WSS** shards, size_t len)
+    Alias(Alias** shards, size_t len)
     : m_reccnt(0), m_tombstone_cnt(0), m_total_weight(0), m_alias(nullptr), m_bf(nullptr) {
         std::vector<Cursor<Wrapped<R>>> cursors;
         cursors.reserve(len);
@@ -195,7 +155,7 @@ public:
         }
    }
 
-    ~WSS() {
+    ~Alias() {
         if (m_data) free(m_data);
         if (m_alias) delete m_alias;
         if (m_bf) delete m_bf;
@@ -247,7 +207,13 @@ public:
         return 0;
     }
 
-private:
+    W get_total_weight() {
+        return m_total_weight;
+    }
+
+    size_t get_weighted_sample(gsl_rng *rng) const {
+        return m_alias->get(rng);
+    }
 
     size_t get_lower_bound(const K& key) const {
         size_t min = 0;
@@ -267,6 +233,8 @@ private:
         return min;
     }
 
+private:
+
     void build_alias_structure(std::vector<W> &weights) {
 
         // normalize the weights vector
@@ -277,11 +245,11 @@ private:
         }
 
         // build the alias structure
-        m_alias = new Alias(norm_weights);
+        m_alias = new psudb::Alias(norm_weights);
     }
 
     Wrapped<R>* m_data;
-    Alias *m_alias;
+    psudb::Alias *m_alias;
     W m_total_weight;
     size_t m_reccnt;
     size_t m_tombstone_cnt;
@@ -289,165 +257,4 @@ private:
     size_t m_alloc_size;
     BloomFilter<R> *m_bf;
 };
-
-
-template <WeightedRecordInterface R, bool Rejection=true>
-class WSSQuery {
-public:
-
-    constexpr static bool EARLY_ABORT=false;
-    constexpr static bool SKIP_DELETE_FILTER=false;
-
-    static void *get_query_state(WSS<R> *wss, void *parms) {
-        auto res = new WSSState<R>();
-        res->total_weight = wss->m_total_weight;
-        res->sample_size = 0;
-
-        return res;
-    }
-
-    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
-        WSSBufferState<R> *state = new WSSBufferState<R>();
-        auto parameters = (wss_query_parms<R>*) parms;
-        if constexpr (Rejection) {
-            state->cutoff = buffer->get_record_count() - 1;
-            state->max_weight = buffer->get_max_weight();
-            state->total_weight = buffer->get_total_weight();
-            return state;
-        }
-
-        std::vector<double> weights;
-
-        state->cutoff = buffer->get_record_count() - 1;
-        double total_weight = 0.0;
-
-        for (size_t i = 0; i <= state->cutoff; i++) {
-            auto rec = buffer->get_data() + i;
-            weights.push_back(rec->rec.weight);
-            total_weight += rec->rec.weight;
-        }
-
-        for (size_t i = 0; i < weights.size(); i++) {
-            weights[i] = weights[i] / total_weight;
-        }
-
-        state->alias = new Alias(weights);
-        state->total_weight = total_weight;
-
-        return state;
-    }
-
-    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, void *buff_state) {
-        auto p = (wss_query_parms<R> *) query_parms;
-        auto bs = (WSSBufferState<R> *) buff_state;
-
-        std::vector<size_t> shard_sample_sizes(shard_states.size()+1, 0);
-        size_t buffer_sz = 0;
-
-        std::vector<decltype(R::weight)> weights;
-        weights.push_back(bs->total_weight);
-
-        decltype(R::weight) total_weight = 0;
-        for (auto &s : shard_states) {
-            auto state = (WSSState<R> *) s;
-            total_weight += state->total_weight;
-            weights.push_back(state->total_weight);
-        }
-
-        std::vector<double> normalized_weights;
-        for (auto w : weights) {
-            normalized_weights.push_back((double) w / (double) total_weight);
-        }
-
-        auto shard_alias = Alias(normalized_weights);
-        for (size_t i=0; i<p->sample_size; i++) {
-            auto idx = shard_alias.get(p->rng);            
-            if (idx == 0) {
-                buffer_sz++;
-            } else {
-                shard_sample_sizes[idx - 1]++;
-            }
-        }
-
-
-        bs->sample_size = buffer_sz;
-        for (size_t i=0; i<shard_states.size(); i++) {
-            auto state = (WSSState<R> *) shard_states[i];
-            state->sample_size = shard_sample_sizes[i+1];
-        }
-    }
-
-    static std::vector<Wrapped<R>> query(WSS<R> *wss, void *q_state, void *parms) { 
-        auto rng = ((wss_query_parms<R> *) parms)->rng;
-
-        auto state = (WSSState<R> *) q_state;
-        auto sample_size = state->sample_size;
-
-        std::vector<Wrapped<R>> result_set;
-
-        if (sample_size == 0) {
-            return result_set;
-        }
-        size_t attempts = 0;
-        do {
-            attempts++;
-            size_t idx = wss->m_alias->get(rng);
-            result_set.emplace_back(*wss->get_record_at(idx));
-        } while (attempts < sample_size);
-
-        return result_set;
-    }
-
-    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
-        auto st = (WSSBufferState<R> *) state;
-        auto p = (wss_query_parms<R> *) parms;
-
-        std::vector<Wrapped<R>> result;
-        result.reserve(st->sample_size);
-
-        if constexpr (Rejection) {
-            for (size_t i=0; i<st->sample_size; i++) {
-                auto idx = gsl_rng_uniform_int(p->rng, st->cutoff);
-                auto rec = buffer->get_data() + idx;
-
-                auto test = gsl_rng_uniform(p->rng) * st->max_weight;
-
-                if (test <= rec->rec.weight) {
-                    result.emplace_back(*rec);
-                }
-            }
-            return result;
-        }
-
-        for (size_t i=0; i<st->sample_size; i++) {
-            auto idx = st->alias->get(p->rng);
-            result.emplace_back(*(buffer->get_data() + idx));
-        }
-
-        return result;
-    }
-
-    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
-        std::vector<R> output;
-
-        for (size_t i=0; i<results.size(); i++) {
-            for (size_t j=0; j<results[i].size(); j++) {
-                output.emplace_back(results[i][j].rec);
-            }
-        }
-
-        return output;
-    }
-
-    static void delete_query_state(void *state) {
-        auto s = (WSSState<R> *) state;
-        delete s;
-    }
-
-    static void delete_buffer_query_state(void *state) {
-        auto s = (WSSBufferState<R> *) state;
-        delete s;
-    }
-};
-
 }
diff --git a/include/shard/WIRS.h b/include/shard/AugBTree.h
index bf29325..e32ec64 100644
--- a/include/shard/WIRS.h
+++ b/include/shard/AugBTree.h
@@ -1,5 +1,5 @@
 /*
- * include/shard/WIRS.h
+ * include/shard/AugBTree.h
  *
  * Copyright (C) 2023 Dong Xie <dongx@psu.edu>
  *                    Douglas B. Rumbaugh <drumbaugh@psu.edu>
@@ -35,73 +35,23 @@ namespace de {
 thread_local size_t wirs_cancelations = 0;
 
 template <WeightedRecordInterface R>
-struct wirs_query_parms {
-    decltype(R::key) lower_bound;
-    decltype(R::key) upper_bound;
-    size_t sample_size;
-    gsl_rng *rng;
-};
-
-template <WeightedRecordInterface R, bool Rejection>
-class WIRSQuery;
-
-template <WeightedRecordInterface R>
-struct wirs_node {
-    struct wirs_node<R> *left, *right;
+struct AugBTreeNode {
+    struct AugBTreeNode<R> *left, *right;
     decltype(R::key) low, high;
     decltype(R::weight) weight;
     Alias* alias;
 };
 
 template <WeightedRecordInterface R>
-struct WIRSState {
-    decltype(R::weight) total_weight;
-    std::vector<wirs_node<R>*> nodes;
-    Alias* top_level_alias;
-    size_t sample_size;
-
-    WIRSState() {
-        total_weight = 0;
-        top_level_alias = nullptr;
-    }
-
-    ~WIRSState() {
-        if (top_level_alias) delete top_level_alias;
-    }
-};
-
-template <WeightedRecordInterface R>
-struct WIRSBufferState {
-    size_t cutoff;
-    Alias* alias;
-    std::vector<Wrapped<R>> records;
-    decltype(R::weight) max_weight;
-    size_t sample_size;
-    decltype(R::weight) total_weight;
-
-    ~WIRSBufferState() {
-        delete alias;
-    }
-
-};
-
-template <WeightedRecordInterface R>
-class WIRS {
+class AugBTree {
 private:
-
     typedef decltype(R::key) K;
     typedef decltype(R::value) V;
     typedef decltype(R::weight) W;
 
 public:
-
-    // FIXME: there has to be a better way to do this
-    friend class WIRSQuery<R, true>;
-    friend class WIRSQuery<R, false>;
-
-    WIRS(MutableBuffer<R>* buffer)
+    AugBTree(MutableBuffer<R>* buffer)
     : m_reccnt(0), m_tombstone_cnt(0), m_total_weight(0), m_root(nullptr) {
-
         m_alloc_size = (buffer->get_record_count() * sizeof(Wrapped<R>)) + (CACHELINE_SIZE - (buffer->get_record_count() * sizeof(Wrapped<R>)) % CACHELINE_SIZE);
         assert(m_alloc_size % CACHELINE_SIZE == 0);
         m_data = (Wrapped<R>*)std::aligned_alloc(CACHELINE_SIZE, m_alloc_size);
@@ -148,7 +98,7 @@ public:
         }
     }
 
-    WIRS(WIRS** shards, size_t len)
+    AugBTree(AugBTree** shards, size_t len)
     : m_reccnt(0), m_tombstone_cnt(0), m_total_weight(0), m_root(nullptr) {
         std::vector<Cursor<Wrapped<R>>> cursors;
         cursors.reserve(len);
@@ -208,7 +158,7 @@ public:
         }
    }
 
-    ~WIRS() {
+    ~AugBTree() {
         if (m_data) free(m_data);
         for (size_t i=0; i<m_alias.size(); i++) {
             if (m_alias[i]) delete m_alias[i];
@@ -257,15 +207,13 @@ public:
 
 
     size_t get_memory_usage() {
-        return m_alloc_size + m_node_cnt * sizeof(wirs_node<Wrapped<R>>);
+        return m_alloc_size + m_node_cnt * sizeof(AugBTreeNode<Wrapped<R>>);
     }
 
     size_t get_aux_memory_usage() {
         return 0;
     }
 
-private:
-
     size_t get_lower_bound(const K& key) const {
         size_t min = 0;
         size_t max = m_reccnt - 1;
@@ -284,13 +232,60 @@ private:
         return min;
     }
 
-    bool covered_by(struct wirs_node<R>* node, const K& lower_key, const K& upper_key) {
+    W find_covering_nodes(K lower_key, K upper_key, std::vector<void *> &nodes, std::vector<W> &weights) {
+        W total_weight = 0;
+        
+        /* Simulate a stack to unfold recursion. */       
+        struct AugBTreeNode<R>* st[64] = {0};
+        st[0] = m_root;
+        size_t top = 1;
+        while(top > 0) {
+            auto now = st[--top];
+            if (covered_by(now, lower_key, upper_key) ||
+                (now->left == nullptr && now->right == nullptr && intersects(now, lower_key, upper_key))) {
+                nodes.emplace_back(now);
+                weights.emplace_back(now->weight);
+                total_weight += now->weight;
+            } else {
+                if (now->left && intersects(now->left, lower_key, upper_key)) st[top++] = now->left;
+                if (now->right && intersects(now->right, lower_key, upper_key)) st[top++] = now->right;
+            }
+        }
+        
+
+        return total_weight;
+    }
+
+    Wrapped<R> *get_weighted_sample(K lower_key, K upper_key, void *internal_node, gsl_rng *rng) {
+        /* k -> sampling: three levels. 1. select a node -> select a fat point -> select a record. */
+
+        /* first level */ 
+        auto node = (AugBTreeNode<R>*) internal_node;
+
+        /* second level */
+        auto fat_point = node->low + node->alias->get(rng);
+
+        /* third level */
+        size_t rec_offset = fat_point * m_group_size + m_alias[fat_point]->get(rng);
+        auto record = m_data + rec_offset;
+
+        /* bounds rejection */
+        if (lower_key > record->rec.key || upper_key < record->rec.key) {
+            return nullptr;
+        } 
+
+        return record;
+    }
+
+private:
+
+    bool covered_by(struct AugBTreeNode<R>* node, const K& lower_key, const K& upper_key) {
         auto low_index = node->low * m_group_size;
         auto high_index = std::min((node->high + 1) * m_group_size - 1, m_reccnt - 1);
         return lower_key < m_data[low_index].rec.key && m_data[high_index].rec.key < upper_key;
     }
 
-    bool intersects(struct wirs_node<R>* node, const K& lower_key, const K& upper_key) {
+    bool intersects(struct AugBTreeNode<R>* node, const K& lower_key, const K& upper_key) {
         auto low_index = node->low * m_group_size;
         auto high_index = std::min((node->high + 1) * m_group_size - 1, m_reccnt - 1);
         return lower_key < m_data[high_index].rec.key && m_data[low_index].rec.key < upper_key;
@@ -327,12 +322,12 @@ private:
 
         assert(weights.size() == n_groups);
 
-        m_root = construct_wirs_node(weights, 0, n_groups-1);
+        m_root = construct_AugBTreeNode(weights, 0, n_groups-1);
     }
 
-     struct wirs_node<R>* construct_wirs_node(const std::vector<W>& weights, size_t low, size_t high) {
+     struct AugBTreeNode<R>* construct_AugBTreeNode(const std::vector<W>& weights, size_t low, size_t high) {
         if (low == high) {
-            return new wirs_node<R>{nullptr, nullptr, low, high, weights[low], new Alias({1.0})};
+            return new AugBTreeNode<R>{nullptr, nullptr, low, high, weights[low], new Alias({1.0})};
         } else if (low > high) return nullptr;
 
         std::vector<double> node_weights;
@@ -348,12 +343,12 @@ private:
         
         m_node_cnt += 1; 
         size_t mid = (low + high) / 2;
-        return new wirs_node<R>{construct_wirs_node(weights, low, mid),
-                                construct_wirs_node(weights, mid + 1, high),
+        return new AugBTreeNode<R>{construct_AugBTreeNode(weights, low, mid),
+                                construct_AugBTreeNode(weights, mid + 1, high),
                                 low, high, sum, new Alias(node_weights)};
     }
 
-    void free_tree(struct wirs_node<R>* node) {
+    void free_tree(struct AugBTreeNode<R>* node) {
         if (node) {
             delete node->alias;
             free_tree(node->left);
@@ -364,7 +359,7 @@ private:
 
     Wrapped<R>* m_data;
     std::vector<Alias *> m_alias;
-    wirs_node<R>* m_root;
+    AugBTreeNode<R>* m_root;
     W m_total_weight;
     size_t m_reccnt;
     size_t m_tombstone_cnt;
@@ -373,222 +368,4 @@ private:
     size_t m_node_cnt;
     BloomFilter<R> *m_bf;
 };
-
-
-template <WeightedRecordInterface R, bool Rejection=true>
-class WIRSQuery {
-public:
-
-    constexpr static bool EARLY_ABORT=false;
-    constexpr static bool SKIP_DELETE_FILTER=false;
-
-    static void *get_query_state(WIRS<R> *wirs, void *parms) {
-        auto res = new WIRSState<R>();
-        decltype(R::key) lower_key = ((wirs_query_parms<R> *) parms)->lower_bound;
-        decltype(R::key) upper_key = ((wirs_query_parms<R> *) parms)->upper_bound;
-
-        // Simulate a stack to unfold recursion.        
-        double total_weight = 0.0;
-        struct wirs_node<R>* st[64] = {0};
-        st[0] = wirs->m_root;
-        size_t top = 1;
-        while(top > 0) {
-            auto now = st[--top];
-            if (wirs->covered_by(now, lower_key, upper_key) ||
-                (now->left == nullptr && now->right == nullptr && wirs->intersects(now, lower_key, upper_key))) {
-                res->nodes.emplace_back(now);
-                total_weight += now->weight;
-            } else {
-                if (now->left && wirs->intersects(now->left, lower_key, upper_key)) st[top++] = now->left;
-                if (now->right && wirs->intersects(now->right, lower_key, upper_key)) st[top++] = now->right;
-            }
-        }
-        
-        std::vector<double> weights;
-        for (const auto& node: res->nodes) {
-            weights.emplace_back(node->weight / total_weight);
-        }
-        res->total_weight = total_weight;
-        res->top_level_alias = new Alias(weights);
-        res->sample_size = 0;
-
-        return res;
-    }
-
-    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
-        WIRSBufferState<R> *state = new WIRSBufferState<R>();
-        auto parameters = (wirs_query_parms<R>*) parms;
-        if constexpr (Rejection) {
-            state->cutoff = buffer->get_record_count() - 1;
-            state->max_weight = buffer->get_max_weight();
-            state->total_weight = buffer->get_total_weight();
-            state->sample_size = 0;
-            return state;
-        }
-
-        std::vector<double> weights;
-
-        state->cutoff = buffer->get_record_count() - 1;
-        double total_weight = 0.0;
-
-        for (size_t i = 0; i <= state->cutoff; i++) {
-            auto rec = buffer->get_data() + i;
-
-            if (rec->rec.key >= parameters->lower_bound && rec->rec.key <= parameters->upper_bound && !rec->is_tombstone() && !rec->is_deleted()) {
-              weights.push_back(rec->rec.weight);
-              state->records.push_back(*rec);
-              total_weight += rec->rec.weight;
-            }
-        }
-
-        for (size_t i = 0; i < weights.size(); i++) {
-            weights[i] = weights[i] / total_weight;
-        }
-
-        state->total_weight = total_weight;
-        state->alias = new Alias(weights);
-        state->sample_size = 0;
-
-        return state;
-    }
-
-    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, std::vector<void*> &buff_states) {
-        // FIXME: need to redo for the buffer vector interface
-        auto p = (wirs_query_parms<R> *) query_parms;
-
-        std::vector<size_t> shard_sample_sizes(shard_states.size()+1, 0);
-        size_t buffer_sz = 0;
-
-        decltype(R::weight) total_weight = 0;
-        std::vector<decltype(R::weight)> weights;
-        for (auto &s : buff_states) {
-            auto state = (WIRSBufferState<R> *) s;
-            total_weight += state->total_weight;
-            weights.push_back(state->total_weight);
-        }
-
-        for (auto &s : shard_states) {
-            auto state = (WIRSState<R> *) s;
-            total_weight += state->total_weight;
-            weights.push_back(state->total_weight);
-        }
-
-        std::vector<double> normalized_weights;
-        for (auto w : weights) {
-            normalized_weights.push_back((double) w / (double) total_weight);
-        }
-
-        auto shard_alias = Alias(normalized_weights);
-        for (size_t i=0; i<p->sample_size; i++) {
-            auto idx = shard_alias.get(p->rng);            
-            if (idx == 0) {
-                buffer_sz++;
-            } else {
-                shard_sample_sizes[idx - 1]++;
-            }
-        }
-
-        for (size_t i=0; i<shard_states.size(); i++) {
-            auto state = (WIRSState<R> *) shard_states[i];
-            state->sample_size = shard_sample_sizes[i+1];
-        }
-    }
-
-
-
-    static std::vector<Wrapped<R>> query(WIRS<R> *wirs, void *q_state, void *parms) { 
-        auto lower_key = ((wirs_query_parms<R> *) parms)->lower_bound;
-        auto upper_key = ((wirs_query_parms<R> *) parms)->upper_bound;
-        auto rng = ((wirs_query_parms<R> *) parms)->rng;
-
-        auto state = (WIRSState<R> *) q_state;
-        auto sample_size = state->sample_size;
-
-        std::vector<Wrapped<R>> result_set;
-
-        if (sample_size == 0) {
-            return result_set;
-        }
-        // k -> sampling: three levels. 1. select a node -> select a fat point -> select a record.
-        size_t cnt = 0;
-        size_t attempts = 0;
-        do {
-            ++attempts;
-            // first level....
-            auto node = state->nodes[state->top_level_alias->get(rng)];
-            // second level...
-            auto fat_point = node->low + node->alias->get(rng);
-            // third level...
-            size_t rec_offset = fat_point * wirs->m_group_size + wirs->m_alias[fat_point]->get(rng);
-            auto record = wirs->m_data + rec_offset;
-
-            // bounds rejection
-            if (lower_key > record->rec.key || upper_key < record->rec.key) {
-                continue;
-            } 
-
-            result_set.emplace_back(*record);
-            cnt++;
-        } while (attempts < sample_size);
-
-        return result_set;
-    }
-
-    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
-        auto st = (WIRSBufferState<R> *) state;
-        auto p = (wirs_query_parms<R> *) parms;
-
-        std::vector<Wrapped<R>> result;
-        result.reserve(st->sample_size);
-
-        if constexpr (Rejection) {
-            for (size_t i=0; i<st->sample_size; i++) {
-                auto idx = gsl_rng_uniform_int(p->rng, st->cutoff);
-                auto rec = buffer->get_data() + idx;
-
-                auto test = gsl_rng_uniform(p->rng) * st->max_weight;
-
-                if (test <= rec->rec.weight && rec->rec.key >= p->lower_bound && rec->rec.key <= p->upper_bound) {
-                    result.emplace_back(*rec);
-                }
-            }
-            return result;
-        }
-
-        for (size_t i=0; i<st->sample_size; i++) {
-            auto idx = st->alias->get(p->rng);
-            result.emplace_back(st->records[idx]);
-        }
-
-        return result;
-    }
-
-    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
-        std::vector<R> output;
-
-        for (size_t i=0; i<results.size(); i++) {
-            for (size_t j=0; j<results[i].size(); j++) {
-                output.emplace_back(results[i][j].rec);
-            }
-        }
-
-        return output;
-    }
-
-    static void delete_query_state(void *state) {
-        auto s = (WIRSState<R> *) state;
-        delete s;
-    }
-
-    static void delete_buffer_query_state(void *state) {
-        auto s = (WIRSBufferState<R> *) state;
-        delete s;
-    }
-
-
-    //{q.get_buffer_query_state(p, p)};
-    //{q.buffer_query(p, p)};
-
-};
-
 }
diff --git a/include/shard/ISAMTree.h b/include/shard/ISAMTree.h
new file mode 100644
index 0000000..a610c09
--- /dev/null
+++ b/include/shard/ISAMTree.h
@@ -0,0 +1,339 @@
+/*
+ * include/shard/ISAMTree.h
+ *
+ * Copyright (C) 2023 Douglas B. Rumbaugh <drumbaugh@psu.edu> 
+ *                    Dong Xie <dongx@psu.edu>
+ *
+ * All rights reserved. Published under the Modified BSD License.
+ *
+ */
+#pragma once
+
+#include <vector>
+#include <cassert>
+#include <queue>
+#include <memory>
+
+#include "framework/ShardRequirements.h"
+
+#include "util/bf_config.h"
+#include "psu-ds/PriorityQueue.h"
+#include "util/Cursor.h"
+#include "psu-util/timer.h"
+
+using psudb::CACHELINE_SIZE;
+using psudb::BloomFilter;
+using psudb::PriorityQueue;
+using psudb::queue_record;
+using psudb::Alias;
+
+namespace de {
+
+thread_local size_t mrun_cancelations = 0;
+
+template <RecordInterface R>
+class ISAMTree {
+private:
+
+typedef decltype(R::key) K;
+typedef decltype(R::value) V;
+
+constexpr static size_t inmem_isam_node_size = 256;
+constexpr static size_t inmem_isam_fanout = inmem_isam_node_size / (sizeof(K) + sizeof(char*));
+
+struct InternalNode {
+    K keys[inmem_isam_fanout];
+    char* child[inmem_isam_fanout];
+};
+
+constexpr static size_t inmem_isam_leaf_fanout = inmem_isam_node_size / sizeof(R);
+constexpr static size_t inmem_isam_node_keyskip = sizeof(K) * inmem_isam_fanout;
+
+static_assert(sizeof(InternalNode) == inmem_isam_node_size, "node size does not match");
+
+public:
+    ISAMTree(MutableBuffer<R>* buffer)
+    :m_reccnt(0), m_tombstone_cnt(0), m_isam_nodes(nullptr), m_deleted_cnt(0) {
+
+        m_bf = new BloomFilter<R>(BF_FPR, buffer->get_tombstone_count(), BF_HASH_FUNCS);
+
+        m_alloc_size = (buffer->get_record_count() * sizeof(Wrapped<R>)) + (CACHELINE_SIZE - (buffer->get_record_count() * sizeof(Wrapped<R>)) % CACHELINE_SIZE);
+        assert(m_alloc_size % CACHELINE_SIZE == 0);
+        m_data = (Wrapped<R>*)std::aligned_alloc(CACHELINE_SIZE, m_alloc_size);
+
+        TIMER_INIT();
+
+        size_t offset = 0;
+        m_reccnt = 0;
+        auto base = buffer->get_data();
+        auto stop = base + buffer->get_record_count();
+
+        TIMER_START();
+        std::sort(base, stop, std::less<Wrapped<R>>());
+        TIMER_STOP();
+        auto sort_time = TIMER_RESULT();
+
+        TIMER_START();
+        while (base < stop) {
+            if (!base->is_tombstone() && (base + 1 < stop)
+                && base->rec == (base + 1)->rec  && (base + 1)->is_tombstone()) {
+                base += 2;
+                mrun_cancelations++;
+                continue;
+            } else if (base->is_deleted()) {
+                base += 1;
+                continue;
+            }
+
+            // FIXME: this shouldn't be necessary, but the tagged record
+            // bypass doesn't seem to be working on this code-path, so this
+            // ensures that tagged records from the buffer are able to be
+            // dropped, eventually. It should only need to be &= 1
+            base->header &= 3;
+            m_data[m_reccnt++] = *base;
+            if (m_bf && base->is_tombstone()) {
+                ++m_tombstone_cnt;
+                m_bf->insert(base->rec);
+            }
+
+            base++;
+        }
+        TIMER_STOP();
+        auto copy_time = TIMER_RESULT();
+
+        TIMER_START();
+        if (m_reccnt > 0) {
+            build_internal_levels();
+        }
+        TIMER_STOP();
+        auto level_time = TIMER_RESULT();
+    }
+
+    ISAMTree(ISAMTree** runs, size_t len)
+    : m_reccnt(0), m_tombstone_cnt(0), m_deleted_cnt(0), m_isam_nodes(nullptr) {
+        std::vector<Cursor<Wrapped<R>>> cursors;
+        cursors.reserve(len);
+
+        PriorityQueue<Wrapped<R>> pq(len);
+
+        size_t attemp_reccnt = 0;
+        size_t tombstone_count = 0;
+        
+        for (size_t i = 0; i < len; ++i) {
+            if (runs[i]) {
+                auto base = runs[i]->get_data();
+                cursors.emplace_back(Cursor{base, base + runs[i]->get_record_count(), 0, runs[i]->get_record_count()});
+                attemp_reccnt += runs[i]->get_record_count();
+                tombstone_count += runs[i]->get_tombstone_count();
+                pq.push(cursors[i].ptr, i);
+            } else {
+                cursors.emplace_back(Cursor<Wrapped<R>>{nullptr, nullptr, 0, 0});
+            }
+        }
+
+        m_bf = new BloomFilter<R>(BF_FPR, tombstone_count, BF_HASH_FUNCS);
+
+        m_alloc_size = (attemp_reccnt * sizeof(Wrapped<R>)) + (CACHELINE_SIZE - (attemp_reccnt * sizeof(Wrapped<R>)) % CACHELINE_SIZE);
+        assert(m_alloc_size % CACHELINE_SIZE == 0);
+        m_data = (Wrapped<R>*)std::aligned_alloc(CACHELINE_SIZE, m_alloc_size);
+
+        size_t offset = 0;
+        
+        while (pq.size()) {
+            auto now = pq.peek();
+            auto next = pq.size() > 1 ? pq.peek(1) : queue_record<Wrapped<R>>{nullptr, 0};
+            if (!now.data->is_tombstone() && next.data != nullptr &&
+                now.data->rec == next.data->rec && next.data->is_tombstone()) {
+                
+                pq.pop(); pq.pop();
+                auto& cursor1 = cursors[now.version];
+                auto& cursor2 = cursors[next.version];
+                if (advance_cursor(cursor1)) pq.push(cursor1.ptr, now.version);
+                if (advance_cursor(cursor2)) pq.push(cursor2.ptr, next.version);
+            } else {
+                auto& cursor = cursors[now.version];
+                if (!cursor.ptr->is_deleted()) {
+                    m_data[m_reccnt++] = *cursor.ptr;
+                    if (cursor.ptr->is_tombstone()) {
+                        ++m_tombstone_cnt;
+                        m_bf->insert(cursor.ptr->rec);
+                    }
+                }
+                pq.pop();
+                
+                if (advance_cursor(cursor)) pq.push(cursor.ptr, now.version);
+            }
+        }
+
+        if (m_reccnt > 0) {
+            build_internal_levels();
+        }
+    }
+
+    ~ISAMTree() {
+        if (m_data) free(m_data);
+        if (m_isam_nodes) free(m_isam_nodes);
+        if (m_bf) delete m_bf;
+    }
+
+    Wrapped<R> *point_lookup(const R &rec, bool filter=false) {
+        if (filter && !m_bf->lookup(rec)) {
+            return nullptr;
+        }
+
+        size_t idx = get_lower_bound(rec.key);
+        if (idx >= m_reccnt) {
+            return nullptr;
+        }
+
+        while (idx < m_reccnt && m_data[idx].rec < rec) ++idx;
+
+        if (m_data[idx].rec == rec) {
+            return m_data + idx;
+        }
+
+        return nullptr;
+    }
+
+    Wrapped<R>* get_data() const {
+        return m_data;
+    }
+    
+    size_t get_record_count() const {
+        return m_reccnt;
+    }
+
+    size_t get_tombstone_count() const {
+        return m_tombstone_cnt;
+    }
+
+    const Wrapped<R>* get_record_at(size_t idx) const {
+        return (idx < m_reccnt) ? m_data + idx : nullptr;
+    }
+
+    size_t get_memory_usage() {
+        return m_internal_node_cnt * inmem_isam_node_size + m_alloc_size;
+    }
+
+    size_t get_aux_memory_usage() {
+        return 0;
+    }
+
+    size_t get_lower_bound(const K& key) const {
+        const InternalNode* now = m_root;
+        while (!is_leaf(reinterpret_cast<const char*>(now))) {
+            const InternalNode* next = nullptr;
+            for (size_t i = 0; i < inmem_isam_fanout - 1; ++i) {
+                if (now->child[i + 1] == nullptr || key <= now->keys[i]) {
+                    next = reinterpret_cast<InternalNode*>(now->child[i]);
+                    break;
+                }
+            }
+
+            now = next ? next : reinterpret_cast<const InternalNode*>(now->child[inmem_isam_fanout - 1]);
+        }
+
+        const Wrapped<R>* pos = reinterpret_cast<const Wrapped<R>*>(now);
+        while (pos < m_data + m_reccnt && pos->rec.key < key) pos++;
+
+        return pos - m_data;
+    }
+
+    size_t get_upper_bound(const K& key) const {
+        const InternalNode* now = m_root;
+        while (!is_leaf(reinterpret_cast<const char*>(now))) {
+            const InternalNode* next = nullptr;
+            for (size_t i = 0; i < inmem_isam_fanout - 1; ++i) {
+                if (now->child[i + 1] == nullptr || key < now->keys[i]) {
+                    next = reinterpret_cast<InternalNode*>(now->child[i]);
+                    break;
+                }
+            }
+
+            now = next ? next : reinterpret_cast<const InternalNode*>(now->child[inmem_isam_fanout - 1]);
+        }
+
+        const Wrapped<R>* pos = reinterpret_cast<const Wrapped<R>*>(now);
+        while (pos < m_data + m_reccnt && pos->rec.key <= key) pos++;
+
+        return pos - m_data;
+    }
+
+
+private:
+    void build_internal_levels() {
+        size_t n_leaf_nodes = m_reccnt / inmem_isam_leaf_fanout + (m_reccnt % inmem_isam_leaf_fanout != 0);
+        size_t level_node_cnt = n_leaf_nodes;
+        size_t node_cnt = 0;
+        do {
+            level_node_cnt = level_node_cnt / inmem_isam_fanout + (level_node_cnt % inmem_isam_fanout != 0);
+            node_cnt += level_node_cnt;
+        } while (level_node_cnt > 1);
+
+        m_alloc_size = (node_cnt * inmem_isam_node_size) + (CACHELINE_SIZE - (node_cnt * inmem_isam_node_size) % CACHELINE_SIZE);
+        assert(m_alloc_size % CACHELINE_SIZE == 0);
+
+        m_isam_nodes = (InternalNode*)std::aligned_alloc(CACHELINE_SIZE, m_alloc_size);
+        m_internal_node_cnt = node_cnt;
+        memset(m_isam_nodes, 0, node_cnt * inmem_isam_node_size);
+
+        InternalNode* current_node = m_isam_nodes;
+
+        const Wrapped<R>* leaf_base = m_data;
+        const Wrapped<R>* leaf_stop = m_data + m_reccnt;
+        while (leaf_base < leaf_stop) {
+            size_t fanout = 0;
+            for (size_t i = 0; i < inmem_isam_fanout; ++i) {
+                auto rec_ptr = leaf_base + inmem_isam_leaf_fanout * i;
+                if (rec_ptr >= leaf_stop) break;
+                const Wrapped<R>* sep_key = std::min(rec_ptr + inmem_isam_leaf_fanout - 1, leaf_stop - 1);
+                current_node->keys[i] = sep_key->rec.key;
+                current_node->child[i] = (char*)rec_ptr;
+                ++fanout;
+            }
+            current_node++;
+            leaf_base += fanout * inmem_isam_leaf_fanout;
+        }
+
+        auto level_start = m_isam_nodes;
+        auto level_stop = current_node;
+        auto current_level_node_cnt = level_stop - level_start;
+        while (current_level_node_cnt > 1) {
+            auto now = level_start;
+            while (now < level_stop) {
+                size_t child_cnt = 0;
+                for (size_t i = 0; i < inmem_isam_fanout; ++i) {
+                    auto node_ptr = now + i;
+                    ++child_cnt;
+                    if (node_ptr >= level_stop) break;
+                    current_node->keys[i] = node_ptr->keys[inmem_isam_fanout - 1];
+                    current_node->child[i] = (char*)node_ptr;
+                }
+                now += child_cnt;
+                current_node++;
+            }
+            level_start = level_stop;
+            level_stop = current_node;
+            current_level_node_cnt = level_stop - level_start;
+        }
+        
+        assert(current_level_node_cnt == 1);
+        m_root = level_start;
+    }
+
+    bool is_leaf(const char* ptr) const {
+        return ptr >= (const char*)m_data && ptr < (const char*)(m_data + m_reccnt);
+    }
+
+    // Members: sorted data, internal ISAM levels, reccnt;
+    Wrapped<R>* m_data;
+    psudb::BloomFilter<R> *m_bf;
+    InternalNode* m_isam_nodes;
+    InternalNode* m_root;
+    size_t m_reccnt;
+    size_t m_tombstone_cnt;
+    size_t m_internal_node_cnt;
+    size_t m_deleted_cnt;
+    size_t m_alloc_size;
+};
+}
diff --git a/include/shard/MemISAM.h b/include/shard/MemISAM.h
deleted file mode 100644
index 00fb467..0000000
--- a/include/shard/MemISAM.h
+++ /dev/null
@@ -1,702 +0,0 @@
-/*
- * include/shard/MemISAM.h
- *
- * Copyright (C) 2023 Douglas B. Rumbaugh <drumbaugh@psu.edu> 
- *                    Dong Xie <dongx@psu.edu>
- *
- * All rights reserved. Published under the Modified BSD License.
- *
- */
-#pragma once
-
-#include <vector>
-#include <cassert>
-#include <queue>
-#include <memory>
-
-#include "framework/ShardRequirements.h"
-
-#include "util/bf_config.h"
-#include "psu-ds/PriorityQueue.h"
-#include "util/Cursor.h"
-#include "psu-util/timer.h"
-
-using psudb::CACHELINE_SIZE;
-using psudb::BloomFilter;
-using psudb::PriorityQueue;
-using psudb::queue_record;
-using psudb::Alias;
-
-namespace de {
-
-thread_local size_t mrun_cancelations = 0;
-
-template <RecordInterface R>
-struct irs_query_parms {
-    decltype(R::key) lower_bound;
-    decltype(R::key) upper_bound;
-    size_t sample_size;
-    gsl_rng *rng;
-};
-
-template <RecordInterface R, bool Rejection>
-class IRSQuery;
-
-template <RecordInterface R>
-struct IRSState {
-    size_t lower_bound;
-    size_t upper_bound;
-    size_t sample_size;
-    size_t total_weight;
-};
-
-template <RecordInterface R>
-struct IRSBufferState {
-    size_t cutoff;
-    std::vector<Wrapped<R>> records;
-    size_t sample_size;
-};
-
-template <RecordInterface R>
-struct ISAMRangeQueryParms {
-    decltype(R::key) lower_bound;
-    decltype(R::key) upper_bound;
-};
-
-template <RecordInterface R>
-class ISAMRangeQuery;
-
-template <RecordInterface R>
-struct ISAMRangeQueryState {
-    size_t start_idx;
-    size_t stop_idx;
-};
-
-template <RecordInterface R>
-struct RangeQueryBufferState {
-    size_t cutoff;
-};
-
-template <RecordInterface R>
-class MemISAM {
-private:
-    friend class IRSQuery<R, true>;
-    friend class IRSQuery<R, false>;
-    friend class ISAMRangeQuery<R>;
-
-typedef decltype(R::key) K;
-typedef decltype(R::value) V;
-
-constexpr static size_t inmem_isam_node_size = 256;
-constexpr static size_t inmem_isam_fanout = inmem_isam_node_size / (sizeof(K) + sizeof(char*));
-
-struct InMemISAMNode {
-    K keys[inmem_isam_fanout];
-    char* child[inmem_isam_fanout];
-};
-
-constexpr static size_t inmem_isam_leaf_fanout = inmem_isam_node_size / sizeof(R);
-constexpr static size_t inmem_isam_node_keyskip = sizeof(K) * inmem_isam_fanout;
-
-static_assert(sizeof(InMemISAMNode) == inmem_isam_node_size, "node size does not match");
-
-public:
-    MemISAM(MutableBuffer<R>* buffer)
-    :m_reccnt(0), m_tombstone_cnt(0), m_isam_nodes(nullptr), m_deleted_cnt(0) {
-
-        m_bf = new BloomFilter<R>(BF_FPR, buffer->get_tombstone_count(), BF_HASH_FUNCS);
-
-        m_alloc_size = (buffer->get_record_count() * sizeof(Wrapped<R>)) + (CACHELINE_SIZE - (buffer->get_record_count() * sizeof(Wrapped<R>)) % CACHELINE_SIZE);
-        assert(m_alloc_size % CACHELINE_SIZE == 0);
-        m_data = (Wrapped<R>*)std::aligned_alloc(CACHELINE_SIZE, m_alloc_size);
-
-        TIMER_INIT();
-
-        size_t offset = 0;
-        m_reccnt = 0;
-        auto base = buffer->get_data();
-        auto stop = base + buffer->get_record_count();
-
-        TIMER_START();
-        std::sort(base, stop, std::less<Wrapped<R>>());
-        TIMER_STOP();
-        auto sort_time = TIMER_RESULT();
-
-        TIMER_START();
-        while (base < stop) {
-            if (!base->is_tombstone() && (base + 1 < stop)
-                && base->rec == (base + 1)->rec  && (base + 1)->is_tombstone()) {
-                base += 2;
-                mrun_cancelations++;
-                continue;
-            } else if (base->is_deleted()) {
-                base += 1;
-                continue;
-            }
-
-            // FIXME: this shouldn't be necessary, but the tagged record
-            // bypass doesn't seem to be working on this code-path, so this
-            // ensures that tagged records from the buffer are able to be
-            // dropped, eventually. It should only need to be &= 1
-            base->header &= 3;
-            m_data[m_reccnt++] = *base;
-            if (m_bf && base->is_tombstone()) {
-                ++m_tombstone_cnt;
-                m_bf->insert(base->rec);
-            }
-
-            base++;
-        }
-        TIMER_STOP();
-        auto copy_time = TIMER_RESULT();
-
-        TIMER_START();
-        if (m_reccnt > 0) {
-            build_internal_levels();
-        }
-        TIMER_STOP();
-        auto level_time = TIMER_RESULT();
-    }
-
-    MemISAM(MemISAM** runs, size_t len)
-    : m_reccnt(0), m_tombstone_cnt(0), m_deleted_cnt(0), m_isam_nodes(nullptr) {
-        std::vector<Cursor<Wrapped<R>>> cursors;
-        cursors.reserve(len);
-
-        PriorityQueue<Wrapped<R>> pq(len);
-
-        size_t attemp_reccnt = 0;
-        size_t tombstone_count = 0;
-        
-        for (size_t i = 0; i < len; ++i) {
-            if (runs[i]) {
-                auto base = runs[i]->get_data();
-                cursors.emplace_back(Cursor{base, base + runs[i]->get_record_count(), 0, runs[i]->get_record_count()});
-                attemp_reccnt += runs[i]->get_record_count();
-                tombstone_count += runs[i]->get_tombstone_count();
-                pq.push(cursors[i].ptr, i);
-            } else {
-                cursors.emplace_back(Cursor<Wrapped<R>>{nullptr, nullptr, 0, 0});
-            }
-        }
-
-        m_bf = new BloomFilter<R>(BF_FPR, tombstone_count, BF_HASH_FUNCS);
-
-        m_alloc_size = (attemp_reccnt * sizeof(Wrapped<R>)) + (CACHELINE_SIZE - (attemp_reccnt * sizeof(Wrapped<R>)) % CACHELINE_SIZE);
-        assert(m_alloc_size % CACHELINE_SIZE == 0);
-        m_data = (Wrapped<R>*)std::aligned_alloc(CACHELINE_SIZE, m_alloc_size);
-
-        size_t offset = 0;
-        
-        while (pq.size()) {
-            auto now = pq.peek();
-            auto next = pq.size() > 1 ? pq.peek(1) : queue_record<Wrapped<R>>{nullptr, 0};
-            if (!now.data->is_tombstone() && next.data != nullptr &&
-                now.data->rec == next.data->rec && next.data->is_tombstone()) {
-                
-                pq.pop(); pq.pop();
-                auto& cursor1 = cursors[now.version];
-                auto& cursor2 = cursors[next.version];
-                if (advance_cursor(cursor1)) pq.push(cursor1.ptr, now.version);
-                if (advance_cursor(cursor2)) pq.push(cursor2.ptr, next.version);
-            } else {
-                auto& cursor = cursors[now.version];
-                if (!cursor.ptr->is_deleted()) {
-                    m_data[m_reccnt++] = *cursor.ptr;
-                    if (cursor.ptr->is_tombstone()) {
-                        ++m_tombstone_cnt;
-                        m_bf->insert(cursor.ptr->rec);
-                    }
-                }
-                pq.pop();
-                
-                if (advance_cursor(cursor)) pq.push(cursor.ptr, now.version);
-            }
-        }
-
-        if (m_reccnt > 0) {
-            build_internal_levels();
-        }
-    }
-
-    ~MemISAM() {
-        if (m_data) free(m_data);
-        if (m_isam_nodes) free(m_isam_nodes);
-        if (m_bf) delete m_bf;
-    }
-
-    Wrapped<R> *point_lookup(const R &rec, bool filter=false) {
-        if (filter && !m_bf->lookup(rec)) {
-            return nullptr;
-        }
-
-        size_t idx = get_lower_bound(rec.key);
-        if (idx >= m_reccnt) {
-            return nullptr;
-        }
-
-        while (idx < m_reccnt && m_data[idx].rec < rec) ++idx;
-
-        if (m_data[idx].rec == rec) {
-            return m_data + idx;
-        }
-
-        return nullptr;
-    }
-
-    Wrapped<R>* get_data() const {
-        return m_data;
-    }
-    
-    size_t get_record_count() const {
-        return m_reccnt;
-    }
-
-    size_t get_tombstone_count() const {
-        return m_tombstone_cnt;
-    }
-
-    const Wrapped<R>* get_record_at(size_t idx) const {
-        return (idx < m_reccnt) ? m_data + idx : nullptr;
-    }
-
-    size_t get_memory_usage() {
-        return m_internal_node_cnt * inmem_isam_node_size + m_alloc_size;
-    }
-
-    size_t get_aux_memory_usage() {
-        return 0;
-    }
-
-private:
-    size_t get_lower_bound(const K& key) const {
-        const InMemISAMNode* now = m_root;
-        while (!is_leaf(reinterpret_cast<const char*>(now))) {
-            const InMemISAMNode* next = nullptr;
-            for (size_t i = 0; i < inmem_isam_fanout - 1; ++i) {
-                if (now->child[i + 1] == nullptr || key <= now->keys[i]) {
-                    next = reinterpret_cast<InMemISAMNode*>(now->child[i]);
-                    break;
-                }
-            }
-
-            now = next ? next : reinterpret_cast<const InMemISAMNode*>(now->child[inmem_isam_fanout - 1]);
-        }
-
-        const Wrapped<R>* pos = reinterpret_cast<const Wrapped<R>*>(now);
-        while (pos < m_data + m_reccnt && pos->rec.key < key) pos++;
-
-        return pos - m_data;
-    }
-
-    size_t get_upper_bound(const K& key) const {
-        const InMemISAMNode* now = m_root;
-        while (!is_leaf(reinterpret_cast<const char*>(now))) {
-            const InMemISAMNode* next = nullptr;
-            for (size_t i = 0; i < inmem_isam_fanout - 1; ++i) {
-                if (now->child[i + 1] == nullptr || key < now->keys[i]) {
-                    next = reinterpret_cast<InMemISAMNode*>(now->child[i]);
-                    break;
-                }
-            }
-
-            now = next ? next : reinterpret_cast<const InMemISAMNode*>(now->child[inmem_isam_fanout - 1]);
-        }
-
-        const Wrapped<R>* pos = reinterpret_cast<const Wrapped<R>*>(now);
-        while (pos < m_data + m_reccnt && pos->rec.key <= key) pos++;
-
-        return pos - m_data;
-    }
-
-    void build_internal_levels() {
-        size_t n_leaf_nodes = m_reccnt / inmem_isam_leaf_fanout + (m_reccnt % inmem_isam_leaf_fanout != 0);
-        size_t level_node_cnt = n_leaf_nodes;
-        size_t node_cnt = 0;
-        do {
-            level_node_cnt = level_node_cnt / inmem_isam_fanout + (level_node_cnt % inmem_isam_fanout != 0);
-            node_cnt += level_node_cnt;
-        } while (level_node_cnt > 1);
-
-        m_alloc_size = (node_cnt * inmem_isam_node_size) + (CACHELINE_SIZE - (node_cnt * inmem_isam_node_size) % CACHELINE_SIZE);
-        assert(m_alloc_size % CACHELINE_SIZE == 0);
-
-        m_isam_nodes = (InMemISAMNode*)std::aligned_alloc(CACHELINE_SIZE, m_alloc_size);
-        m_internal_node_cnt = node_cnt;
-        memset(m_isam_nodes, 0, node_cnt * inmem_isam_node_size);
-
-        InMemISAMNode* current_node = m_isam_nodes;
-
-        const Wrapped<R>* leaf_base = m_data;
-        const Wrapped<R>* leaf_stop = m_data + m_reccnt;
-        while (leaf_base < leaf_stop) {
-            size_t fanout = 0;
-            for (size_t i = 0; i < inmem_isam_fanout; ++i) {
-                auto rec_ptr = leaf_base + inmem_isam_leaf_fanout * i;
-                if (rec_ptr >= leaf_stop) break;
-                const Wrapped<R>* sep_key = std::min(rec_ptr + inmem_isam_leaf_fanout - 1, leaf_stop - 1);
-                current_node->keys[i] = sep_key->rec.key;
-                current_node->child[i] = (char*)rec_ptr;
-                ++fanout;
-            }
-            current_node++;
-            leaf_base += fanout * inmem_isam_leaf_fanout;
-        }
-
-        auto level_start = m_isam_nodes;
-        auto level_stop = current_node;
-        auto current_level_node_cnt = level_stop - level_start;
-        while (current_level_node_cnt > 1) {
-            auto now = level_start;
-            while (now < level_stop) {
-                size_t child_cnt = 0;
-                for (size_t i = 0; i < inmem_isam_fanout; ++i) {
-                    auto node_ptr = now + i;
-                    ++child_cnt;
-                    if (node_ptr >= level_stop) break;
-                    current_node->keys[i] = node_ptr->keys[inmem_isam_fanout - 1];
-                    current_node->child[i] = (char*)node_ptr;
-                }
-                now += child_cnt;
-                current_node++;
-            }
-            level_start = level_stop;
-            level_stop = current_node;
-            current_level_node_cnt = level_stop - level_start;
-        }
-        
-        assert(current_level_node_cnt == 1);
-        m_root = level_start;
-    }
-
-    bool is_leaf(const char* ptr) const {
-        return ptr >= (const char*)m_data && ptr < (const char*)(m_data + m_reccnt);
-    }
-
-    // Members: sorted data, internal ISAM levels, reccnt;
-    Wrapped<R>* m_data;
-    psudb::BloomFilter<R> *m_bf;
-    InMemISAMNode* m_isam_nodes;
-    InMemISAMNode* m_root;
-    size_t m_reccnt;
-    size_t m_tombstone_cnt;
-    size_t m_internal_node_cnt;
-    size_t m_deleted_cnt;
-    size_t m_alloc_size;
-};
-
-template <RecordInterface R, bool Rejection=true>
-class IRSQuery {
-public:
-
-    constexpr static bool EARLY_ABORT=false;
-    constexpr static bool SKIP_DELETE_FILTER=false;
-
-    static void *get_query_state(MemISAM<R> *isam, void *parms) {
-        auto res = new IRSState<R>();
-        decltype(R::key) lower_key = ((irs_query_parms<R> *) parms)->lower_bound;
-        decltype(R::key) upper_key = ((irs_query_parms<R> *) parms)->upper_bound;
-
-        res->lower_bound = isam->get_lower_bound(lower_key);
-        res->upper_bound = isam->get_upper_bound(upper_key);
-
-        if (res->lower_bound == isam->get_record_count()) {
-            res->total_weight = 0;
-        } else {
-            res->total_weight = res->upper_bound - res->lower_bound;
-        }
-
-        res->sample_size = 0;
-        return res;
-    }
-
-    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
-        auto res = new IRSBufferState<R>();
-
-        res->cutoff = buffer->get_record_count();
-        res->sample_size = 0;
-
-        if constexpr (Rejection) {
-            return res;
-        }
-
-        auto lower_key = ((irs_query_parms<R> *) parms)->lower_bound;
-        auto upper_key = ((irs_query_parms<R> *) parms)->upper_bound;
-
-        for (size_t i=0; i<res->cutoff; i++) {
-            if (((buffer->get_data() + i)->rec.key >= lower_key) && ((buffer->get_data() + i)->rec.key <= upper_key)) { 
-                res->records.emplace_back(*(buffer->get_data() + i));
-            }
-        }
-
-        return res;
-    }
-
-    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, void *buff_state) {
-        auto p = (irs_query_parms<R> *) query_parms;
-        auto bs = (buff_state) ? (IRSBufferState<R> *) buff_state : nullptr;
-
-        std::vector<size_t> shard_sample_sizes(shard_states.size()+1, 0);
-        size_t buffer_sz = 0;
-
-        std::vector<size_t> weights;
-        if constexpr (Rejection) {
-            weights.push_back((bs) ? bs->cutoff : 0);
-        } else {
-            weights.push_back((bs) ? bs->records.size() : 0);
-        }
-
-        size_t total_weight = 0;
-        for (auto &s : shard_states) {
-            auto state = (IRSState<R> *) s;
-            total_weight += state->total_weight;
-            weights.push_back(state->total_weight);
-        }
-
-        // if no valid records fall within the query range, just
-        // set all of the sample sizes to 0 and bail out.
-        if (total_weight == 0) {
-            for (size_t i=0; i<shard_states.size(); i++) {
-                auto state = (IRSState<R> *) shard_states[i];
-                state->sample_size = 0;
-            }
-
-            return;
-        }
-
-        std::vector<double> normalized_weights;
-        for (auto w : weights) {
-            normalized_weights.push_back((double) w / (double) total_weight);
-        }
-
-        auto shard_alias = Alias(normalized_weights);
-        for (size_t i=0; i<p->sample_size; i++) {
-            auto idx = shard_alias.get(p->rng);            
-            if (idx == 0) {
-                buffer_sz++;
-            } else {
-                shard_sample_sizes[idx - 1]++;
-            }
-        }
-
-        if (bs) {
-            bs->sample_size = buffer_sz;
-        }
-        for (size_t i=0; i<shard_states.size(); i++) {
-            auto state = (IRSState<R> *) shard_states[i];
-            state->sample_size = shard_sample_sizes[i+1];
-        }
-    }
-
-    static std::vector<Wrapped<R>> query(MemISAM<R> *isam, void *q_state, void *parms) { 
-        auto lower_key = ((irs_query_parms<R> *) parms)->lower_bound;
-        auto upper_key = ((irs_query_parms<R> *) parms)->upper_bound;
-        auto rng = ((irs_query_parms<R> *) parms)->rng;
-
-        auto state = (IRSState<R> *) q_state;
-        auto sample_sz = state->sample_size;
-
-        std::vector<Wrapped<R>> result_set;
-
-        if (sample_sz == 0 || state->lower_bound == isam->get_record_count()) {
-            return result_set;
-        }
-
-        size_t attempts = 0;
-        size_t range_length = state->upper_bound - state->lower_bound;
-        do {
-            attempts++;
-            size_t idx = (range_length > 0) ? gsl_rng_uniform_int(rng, range_length) : 0;
-            result_set.emplace_back(*isam->get_record_at(state->lower_bound + idx));
-        } while (attempts < sample_sz);
-
-        return result_set;
-    }
-
-    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
-        auto st = (IRSBufferState<R> *) state;
-        auto p = (irs_query_parms<R> *) parms;
-
-        std::vector<Wrapped<R>> result;
-        result.reserve(st->sample_size);
-
-        if constexpr (Rejection) {
-            for (size_t i=0; i<st->sample_size; i++) {
-                auto idx = gsl_rng_uniform_int(p->rng, st->cutoff);
-                auto rec = buffer->get_data() + idx;
-
-                if (rec->rec.key >= p->lower_bound && rec->rec.key <= p->upper_bound) {
-                    result.emplace_back(*rec);
-                }
-            }
-
-            return result;
-        }
-
-        for (size_t i=0; i<st->sample_size; i++) {
-            auto idx = gsl_rng_uniform_int(p->rng, st->records.size());
-            result.emplace_back(st->records[idx]);
-        }
-
-        return result;
-    }
-
-    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
-        std::vector<R> output;
-
-        for (size_t i=0; i<results.size(); i++) {
-            for (size_t j=0; j<results[i].size(); j++) {
-                output.emplace_back(results[i][j].rec);
-            }
-        }
-
-        return output;
-    }
-
-    static void delete_query_state(void *state) {
-        auto s = (IRSState<R> *) state;
-        delete s;
-    }
-
-    static void delete_buffer_query_state(void *state) {
-        auto s = (IRSBufferState<R> *) state;
-        delete s;
-    }
-};
-
-
-template <RecordInterface R>
-class ISAMRangeQuery {
-public:
-
-    constexpr static bool EARLY_ABORT=false;
-    constexpr static bool SKIP_DELETE_FILTER=true;
-
-    static void *get_query_state(MemISAM<R> *ts, void *parms) {
-        auto res = new ISAMRangeQueryState<R>();
-        auto p = (ISAMRangeQueryParms<R> *) parms;
-
-        res->start_idx = ts->get_lower_bound(p->lower_bound);
-        res->stop_idx = ts->get_record_count();
-
-        return res;
-    }
-
-    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
-        auto res = new RangeQueryBufferState<R>();
-        res->cutoff = buffer->get_record_count();
-
-        return res;
-    }
-
-    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, std::vector<void*> &buffer_states) {
-        return;
-    }
-
-    static std::vector<Wrapped<R>> query(MemISAM<R> *ts, void *q_state, void *parms) {
-        std::vector<Wrapped<R>> records;
-        auto p = (ISAMRangeQueryParms<R> *) parms;
-        auto s = (ISAMRangeQueryState<R> *) q_state;
-
-        // if the returned index is one past the end of the
-        // records for the PGM, then there are not records
-        // in the index falling into the specified range.
-        if (s->start_idx == ts->get_record_count()) {
-            return records;
-        }
-
-        auto ptr = ts->get_record_at(s->start_idx);
-        
-        // roll the pointer forward to the first record that is
-        // greater than or equal to the lower bound.
-        while(ptr->rec.key < p->lower_bound) {
-            ptr++;
-        }
-
-        while (ptr->rec.key <= p->upper_bound && ptr < ts->m_data + s->stop_idx) {
-            records.emplace_back(*ptr);
-            ptr++;
-        }
-
-        return records;
-    }
-
-    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
-        auto p = (ISAMRangeQueryParms<R> *) parms;
-        auto s = (RangeQueryBufferState<R> *) state;
-
-        std::vector<Wrapped<R>> records;
-        for (size_t i=0; i<s->cutoff; i++) {
-            auto rec = buffer->get_data() + i;
-            if (rec->rec.key >= p->lower_bound && rec->rec.key <= p->upper_bound) {
-                records.emplace_back(*rec);
-            }
-        }
-
-        return records;
-    }
-
-    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
-        std::vector<Cursor<Wrapped<R>>> cursors;
-        cursors.reserve(results.size());
-
-        PriorityQueue<Wrapped<R>> pq(results.size());
-        size_t total = 0;
-		size_t tmp_n = results.size();
-        
-
-        for (size_t i = 0; i < tmp_n; ++i)
-			if (results[i].size() > 0){
-	            auto base = results[i].data();
-		        cursors.emplace_back(Cursor{base, base + results[i].size(), 0, results[i].size()});
-				assert(i == cursors.size() - 1);
-			    total += results[i].size();
-				pq.push(cursors[i].ptr, tmp_n - i - 1);
-			} else {
-				cursors.emplace_back(Cursor<Wrapped<R>>{nullptr, nullptr, 0, 0});
-			}
-
-        if (total == 0) {
-            return std::vector<R>();
-        }
-
-        std::vector<R> output;
-        output.reserve(total);
-
-        while (pq.size()) {
-            auto now = pq.peek();
-            auto next = pq.size() > 1 ? pq.peek(1) : queue_record<Wrapped<R>>{nullptr, 0};
-            if (!now.data->is_tombstone() && next.data != nullptr &&
-                now.data->rec == next.data->rec && next.data->is_tombstone()) {
-                
-                pq.pop(); pq.pop();
-                auto& cursor1 = cursors[tmp_n - now.version - 1];
-                auto& cursor2 = cursors[tmp_n - next.version - 1];
-                if (advance_cursor<Wrapped<R>>(cursor1)) pq.push(cursor1.ptr, now.version);
-                if (advance_cursor<Wrapped<R>>(cursor2)) pq.push(cursor2.ptr, next.version);
-            } else {
-                auto& cursor = cursors[tmp_n - now.version - 1];
-                if (!now.data->is_tombstone()) output.push_back(cursor.ptr->rec);
-                pq.pop();
-                
-                if (advance_cursor<Wrapped<R>>(cursor)) pq.push(cursor.ptr, now.version);
-            }
-        }
-
-        return output;
-    }
-
-    static void delete_query_state(void *state) {
-        auto s = (ISAMRangeQueryState<R> *) state;
-        delete s;
-    }
-
-    static void delete_buffer_query_state(void *state) {
-        auto s = (RangeQueryBufferState<R> *) state;
-        delete s;
-    }
-};
-
-
-
-}
diff --git a/include/shard/PGM.h b/include/shard/PGM.h
index 6d76376..6b66b7d 100644
--- a/include/shard/PGM.h
+++ b/include/shard/PGM.h
@@ -31,34 +31,6 @@ using psudb::Alias;
 
 namespace de {
 
-template <RecordInterface R>
-struct pgm_range_query_parms {
-    decltype(R::key) lower_bound;
-    decltype(R::key) upper_bound;
-};
-
-template <RecordInterface R>
-struct PGMPointLookupParms {
-    decltype(R::key) target_key;
-};
-
-template <RecordInterface R>
-class PGMRangeQuery;
-
-template <RecordInterface R>
-class PGMPointLookup;
-
-template <RecordInterface R>
-struct PGMState {
-    size_t start_idx;
-    size_t stop_idx;
-};
-
-template <RecordInterface R>
-struct PGMBufferState {
-    size_t cutoff;
-};
-
 template <RecordInterface R, size_t epsilon=128>
 class PGM {
 private:
@@ -67,11 +39,6 @@ private:
 
 
 public:
-
-    // FIXME: there has to be a better way to do this
-    friend class PGMRangeQuery<R>;
-    friend class PGMPointLookup<R>;
-
     PGM(MutableBuffer<R>* buffer)
     : m_reccnt(0), m_tombstone_cnt(0) {
 
@@ -80,8 +47,6 @@ public:
         m_data = (Wrapped<R>*)std::aligned_alloc(CACHELINE_SIZE, m_alloc_size);
         std::vector<K> keys;
 
-        //m_bf = new BloomFilter<R>(BF_FPR, buffer->get_tombstone_count(), BF_HASH_FUNCS);
-
         size_t offset = 0;
         m_reccnt = 0;
         auto base = buffer->get_data();
@@ -110,13 +75,6 @@ public:
             base->header &= 3;
             m_data[m_reccnt++] = *base;
             keys.emplace_back(base->rec.key);
-			
-			/*
-            if (m_bf && base->is_tombstone()) {
-                m_tombstone_cnt++;
-                m_bf->insert(base->rec);
-            }*/
-            
             base++;
         }
 
@@ -148,8 +106,6 @@ public:
             }
         }
 
-        //m_bf = new BloomFilter<R>(BF_FPR, tombstone_count, BF_HASH_FUNCS);
-
         m_alloc_size = (attemp_reccnt * sizeof(Wrapped<R>)) + (CACHELINE_SIZE - (attemp_reccnt * sizeof(Wrapped<R>)) % CACHELINE_SIZE);
         assert(m_alloc_size % CACHELINE_SIZE == 0);
         m_data = (Wrapped<R>*)std::aligned_alloc(CACHELINE_SIZE, m_alloc_size);
@@ -172,10 +128,6 @@ public:
                 if (!cursor.ptr->is_deleted()) {
                     m_data[m_reccnt++] = *cursor.ptr;
                     keys.emplace_back(cursor.ptr->rec.key);
-                    /*if (m_bf && cursor.ptr->is_tombstone()) {
-                        ++m_tombstone_cnt;
-                        if (m_bf) m_bf->insert(cursor.ptr->rec);
-                    }*/
                 }
                 pq.pop();
                 
@@ -190,15 +142,9 @@ public:
 
     ~PGM() {
         if (m_data) free(m_data);
-        //if (m_bf) delete m_bf;
-
     }
 
     Wrapped<R> *point_lookup(const R &rec, bool filter=false) {
-        //if (filter && !m_bf->lookup(rec)) {
-        //    return nullptr;
-        //}
-
         size_t idx = get_lower_bound(rec.key);
         if (idx >= m_reccnt) {
             return nullptr;
@@ -284,219 +230,6 @@ private:
     K m_max_key;
     K m_min_key;
     pgm::PGMIndex<K, epsilon> m_pgm;
-    //BloomFilter<R> *m_bf;
-};
-template <RecordInterface R>
-class PGMPointLookup {
-public:
-    constexpr static bool EARLY_ABORT=false;
-    constexpr static bool SKIP_DELETE_FILTER=false;
-
-    static void *get_query_state(PGM<R> *ts, void *parms) {
-        return nullptr;
-    }
-
-    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
-        return nullptr;
-    }
-
-    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, void *buff_state) {
-        return;
-    }
-
-    static std::vector<Wrapped<R>> query(PGM<R> *ts, void *q_state, void *parms) {
-        std::vector<Wrapped<R>> records;
-        auto p = (PGMPointLookupParms<R> *) parms;
-        auto s = (PGMState<R> *) q_state;
-
-        size_t idx = ts->get_lower_bound(p->target_key);
-        if (ts->get_record_at(idx)->rec.key == p->target_key) {
-            records.emplace_back(*ts->get_record_at(idx));
-        }
-
-        return records;
-    }
-
-    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
-        auto p = (PGMPointLookupParms<R> *) parms;
-        auto s = (PGMBufferState<R> *) state;
-
-        std::vector<Wrapped<R>> records;
-        for (size_t i=0; i<buffer->get_record_count(); i++) {
-            auto rec = buffer->get_data() + i;
-            if (rec->rec.key == p->target_key) {
-                records.emplace_back(*rec);
-                return records;
-            }
-        }
-
-        return records;
-    }
-
-    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
-        std::vector<R> output;
-        for (size_t i=0 ;i<results.size(); i++) {
-            if (results[i].size() > 0) {
-                output.emplace_back(results[i][0].rec);
-                return output;
-            }
-        }
-
-        return output;
-    }
-
-    static void delete_query_state(void *state) {
-    }
-
-    static void delete_buffer_query_state(void *state) {
-    }
 };
 
-
-
-template <RecordInterface R>
-class PGMRangeQuery {
-public:
-    constexpr static bool EARLY_ABORT=false;
-	constexpr static bool SKIP_DELETE_FILTER=false;
-
-    static void *get_query_state(PGM<R> *ts, void *parms) {
-        auto res = new PGMState<R>();
-        auto p = (pgm_range_query_parms<R> *) parms;
-
-        res->start_idx = ts->get_lower_bound(p->lower_bound);
-        res->stop_idx = ts->get_record_count();
-
-        return res;
-    }
-
-    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
-        auto res = new PGMBufferState<R>();
-        res->cutoff = buffer->get_record_count();
-
-        return res;
-    }
-
-    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, void *buff_state) {
-        return;
-    }
-
-    static std::vector<Wrapped<R>> query(PGM<R> *ts, void *q_state, void *parms) {
-		size_t tot = 0;
-        //std::vector<Wrapped<R>> records;
-        auto p = (pgm_range_query_parms<R> *) parms;
-        auto s = (PGMState<R> *) q_state;
-
-        // if the returned index is one past the end of the
-        // records for the PGM, then there are not records
-        // in the index falling into the specified range.
-        if (s->start_idx == ts->get_record_count()) {
-            return {};
-        }
-
-        auto ptr = ts->get_record_at(s->start_idx);
-        
-        // roll the pointer forward to the first record that is
-        // greater than or equal to the lower bound.
-        while(ptr->rec.key < p->lower_bound) {
-            ptr++;
-        }
-
-        while (ptr->rec.key <= p->upper_bound && ptr < ts->m_data + s->stop_idx) {
-            if (ptr->is_tombstone()) --tot;
-			else if (!ptr->is_deleted()) ++tot;
-			//records.emplace_back(*ptr);
-            ptr++;
-        }
-
-		return {Wrapped<R>{0, {tot, 0}}};
-        //return records;
-    }
-
-    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
-		size_t tot = 0;
-        auto p = (pgm_range_query_parms<R> *) parms;
-        auto s = (PGMBufferState<R> *) state;
-
-        //std::vector<Wrapped<R>> records;
-        for (size_t i=0; i<s->cutoff; i++) {
-            auto rec = buffer->get_data() + i;
-            if (rec->rec.key >= p->lower_bound && rec->rec.key <= p->upper_bound) {
-				if (rec->is_tombstone()) --tot;
-				else if (!rec->is_deleted()) ++tot;
-                //records.emplace_back(*rec);
-            }
-        }
-
-		return {Wrapped<R>{0, {tot, 0}}};
-        //return records;
-    }
-
-    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
-		/*std::vector<Cursor<Wrapped<R>>> cursors;
-        cursors.reserve(results.size());
-
-        PriorityQueue<Wrapped<R>> pq(results.size());
-        size_t total = 0;
-		size_t tmp_n = results.size();
-        
-
-        for (size_t i = 0; i < tmp_n; ++i)
-			if (results[i].size() > 0){
-	            auto base = results[i].data();
-		        cursors.emplace_back(Cursor{base, base + results[i].size(), 0, results[i].size()});
-				assert(i == cursors.size() - 1);
-			    total += results[i].size();
-				pq.push(cursors[i].ptr, tmp_n - i - 1);
-			} else {
-				cursors.emplace_back(Cursor<Wrapped<R>>{nullptr, nullptr, 0, 0});
-			}
-
-        if (total == 0) {
-            return std::vector<R>();
-        }
-
-        std::vector<R> output;
-        output.reserve(total);
-
-        while (pq.size()) {
-            auto now = pq.peek();
-            auto next = pq.size() > 1 ? pq.peek(1) : queue_record<Wrapped<R>>{nullptr, 0};
-            if (!now.data->is_tombstone() && next.data != nullptr &&
-                now.data->rec == next.data->rec && next.data->is_tombstone()) {
-                
-                pq.pop(); pq.pop();
-                auto& cursor1 = cursors[tmp_n - now.version - 1];
-                auto& cursor2 = cursors[tmp_n - next.version - 1];
-                if (advance_cursor<Wrapped<R>>(cursor1)) pq.push(cursor1.ptr, now.version);
-                if (advance_cursor<Wrapped<R>>(cursor2)) pq.push(cursor2.ptr, next.version);
-            } else {
-                auto& cursor = cursors[tmp_n - now.version - 1];
-                if (!now.data->is_tombstone()) output.push_back(cursor.ptr->rec);
-                pq.pop();
-                
-                if (advance_cursor<Wrapped<R>>(cursor)) pq.push(cursor.ptr, now.version);
-            }
-        }*/
-
-		size_t tot = 0;
-		for (auto& result: results)
-			if (result.size() > 0) tot += result[0].rec.key;
-
-        return {{tot, 0}};
-    }
-
-    static void delete_query_state(void *state) {
-        auto s = (PGMState<R> *) state;
-        delete s;
-    }
-
-    static void delete_buffer_query_state(void *state) {
-        auto s = (PGMBufferState<R> *) state;
-        delete s;
-    }
-};
-
-;
-
 }
diff --git a/include/shard/TrieSpline.h b/include/shard/TrieSpline.h
index a784a38..fdf8edb 100644
--- a/include/shard/TrieSpline.h
+++ b/include/shard/TrieSpline.h
@@ -30,32 +30,6 @@ using psudb::Alias;
 
 namespace de {
 
-template <RecordInterface R>
-struct ts_range_query_parms {
-    decltype(R::key) lower_bound;
-    decltype(R::key) upper_bound;
-};
-
-template <RecordInterface R>
-class TrieSplineRangeQuery;
-
-template <RecordInterface R>
-struct TrieSplineState {
-    size_t start_idx;
-    size_t stop_idx;
-};
-
-template <RecordInterface R>
-struct TrieSplineBufferState {
-    size_t cutoff;
-    Alias* alias;
-
-    ~TrieSplineBufferState() {
-        delete alias;
-    }
-
-};
-
 template <RecordInterface R, size_t E=1024>
 class TrieSpline {
 private:
@@ -63,10 +37,6 @@ private:
     typedef decltype(R::value) V;
 
 public:
-
-    // FIXME: there has to be a better way to do this
-    friend class TrieSplineRangeQuery<R>;
-
     TrieSpline(MutableBuffer<R>* buffer)
     : m_reccnt(0), m_tombstone_cnt(0) {
 
@@ -254,8 +224,6 @@ public:
         return 0;
     }
 
-private:
-
     size_t get_lower_bound(const K& key) const {
         auto bound = m_ts.GetSearchBound(key);
         size_t idx = bound.begin;
@@ -293,6 +261,8 @@ private:
         return (m_data[idx].rec.key <= key) ? idx : m_reccnt;
     }
 
+private:
+
     Wrapped<R>* m_data;
     size_t m_reccnt;
     size_t m_tombstone_cnt;
@@ -302,154 +272,4 @@ private:
     ts::TrieSpline<K> m_ts;
     BloomFilter<R> *m_bf;
 };
-
-
-template <RecordInterface R>
-class TrieSplineRangeQuery {
-public:
-    constexpr static bool EARLY_ABORT=false;
-    constexpr static bool SKIP_DELETE_FILTER=true;
-
-    static void *get_query_state(TrieSpline<R> *ts, void *parms) {
-        auto res = new TrieSplineState<R>();
-        auto p = (ts_range_query_parms<R> *) parms;
-
-        res->start_idx = ts->get_lower_bound(p->lower_bound);
-        res->stop_idx = ts->get_record_count();
-
-        return res;
-    }
-
-    static void* get_buffer_query_state(MutableBuffer<R> *buffer, void *parms) {
-        auto res = new TrieSplineBufferState<R>();
-        res->cutoff = buffer->get_record_count();
-
-        return res;
-    }
-
-    static void process_query_states(void *query_parms, std::vector<void*> &shard_states, void *buff_state) {
-        return;
-    }
-
-    static std::vector<Wrapped<R>> query(TrieSpline<R> *ts, void *q_state, void *parms) {
-        //std::vector<Wrapped<R>> records;
-		size_t tot = 0;
-        auto p = (ts_range_query_parms<R> *) parms;
-        auto s = (TrieSplineState<R> *) q_state;
-
-        // if the returned index is one past the end of the
-        // records for the TrieSpline, then there are not records
-        // in the index falling into the specified range.
-        if (s->start_idx == ts->get_record_count()) {
-            return {};
-        }
-
-        auto ptr = ts->get_record_at(s->start_idx);
-
-        // roll the pointer forward to the first record that is
-        // greater than or equal to the lower bound.
-        while(ptr->rec.key < p->lower_bound) {
-            ptr++;
-        }
-
-
-        while (ptr->rec.key <= p->upper_bound && ptr < ts->m_data + s->stop_idx) {
-            if (ptr->is_tombstone()) --tot;
-			else if (!ptr->is_deleted()) ++tot;
-            //records.emplace_back(*ptr);
-            ptr++;
-        }
-
-		return {Wrapped<R>{0, {tot, 0}}};
-        //return records;
-    }
-
-    static std::vector<Wrapped<R>> buffer_query(MutableBuffer<R> *buffer, void *state, void *parms) {
-		size_t tot = 0;
-        auto p = (ts_range_query_parms<R> *) parms;
-        auto s = (TrieSplineBufferState<R> *) state;
-
-        //std::vector<Wrapped<R>> records;
-        for (size_t i=0; i<s->cutoff; i++) {
-            auto rec = buffer->get_data() + i;
-            if (rec->rec.key >= p->lower_bound && rec->rec.key <= p->upper_bound) {
-				if (rec->is_tombstone()) --tot;
-				else if (!rec->is_deleted()) ++tot;
-                //records.emplace_back(*rec);
-            }
-
-        }
-
-		return {Wrapped<R>{0, {tot, 0}}};
-        //return records;
-    }
-
-    static std::vector<R> merge(std::vector<std::vector<Wrapped<R>>> &results, void *parms) {
-/*
-		std::vector<Cursor<Wrapped<R>>> cursors;
-        cursors.reserve(results.size());
-
-        PriorityQueue<Wrapped<R>> pq(results.size());
-        size_t total = 0;
-        size_t tmp_n = results.size();
-
-
-        for (size_t i = 0; i < tmp_n; ++i)
-            if (results[i].size() > 0){
-                auto base = results[i].data();
-                cursors.emplace_back(Cursor{base, base + results[i].size(), 0, results[i].size()});
-                assert(i == cursors.size() - 1);
-                total += results[i].size();
-                pq.push(cursors[i].ptr, tmp_n - i - 1);
-            } else {
-                cursors.emplace_back(Cursor<Wrapped<R>>{nullptr, nullptr, 0, 0});
-            }
-
-        if (total == 0) {
-            return std::vector<R>();
-        }
-
-        std::vector<R> output;
-        output.reserve(total);
-
-        while (pq.size()) {
-            auto now = pq.peek();
-            auto next = pq.size() > 1 ? pq.peek(1) : queue_record<Wrapped<R>>{nullptr, 0};
-            if (!now.data->is_tombstone() && next.data != nullptr &&
-                now.data->rec == next.data->rec && next.data->is_tombstone()) {
-                
-                pq.pop(); pq.pop();
-                auto& cursor1 = cursors[tmp_n - now.version - 1];
-                auto& cursor2 = cursors[tmp_n - next.version - 1];
-                if (advance_cursor<Wrapped<R>>(cursor1)) pq.push(cursor1.ptr, now.version);
-                if (advance_cursor<Wrapped<R>>(cursor2)) pq.push(cursor2.ptr, next.version);
-            } else {
-                auto& cursor = cursors[tmp_n - now.version - 1];
-                if (!now.data->is_tombstone()) output.push_back(cursor.ptr->rec);
-                pq.pop();
-                
-                if (advance_cursor<Wrapped<R>>(cursor)) pq.push(cursor.ptr, now.version);
-            }
-        }
-
-        return output;*/
-
-		size_t tot = 0;
-		for (auto& result: results)
-			if (result.size() > 0) tot += result[0].rec.key;
-
-        return {{tot, 0}};
-    }
-
-    static void delete_query_state(void *state) {
-        auto s = (TrieSplineState<R> *) state;
-        delete s;
-    }
-
-    static void delete_buffer_query_state(void *state) {
-        auto s = (TrieSplineBufferState<R> *) state;
-        delete s;
-    }
-};
-
 }
diff --git a/tests/wss_tests.cpp b/tests/alias_tests.cpp
index cdc8001..c4a302d 100644
--- a/tests/wss_tests.cpp
+++ b/tests/alias_tests.cpp
@@ -1,7 +1,7 @@
 /*
- * tests/wss_tests.cpp
+ * tests/alias_tests.cpp
  *
- * Unit tests for WSS (Augmented B+Tree) shard
+ * Unit tests for Alias shard
  *
  * Copyright (C) 2023 Douglas Rumbaugh <drumbaugh@psu.edu> 
  *                    Dong Xie <dongx@psu.edu>
@@ -10,14 +10,15 @@
  *
  */
 
-#include "shard/WSS.h"
+#include "shard/Alias.h"
+#include "query/wss.h"
 #include "testing.h"
 
 #include <check.h>
 
 using namespace de;
 
-typedef WSS<WRec> Shard;
+typedef Alias<WRec> Shard;
 
 START_TEST(t_mbuffer_init)
 {
@@ -45,7 +46,7 @@ START_TEST(t_mbuffer_init)
 }
 
 
-START_TEST(t_wss_init)
+START_TEST(t_alias_init)
 {
     size_t n = 512;
     auto mbuffer1 = create_test_mbuffer<WRec>(n);
@@ -101,7 +102,7 @@ START_TEST(t_point_lookup)
     size_t n = 10000;
 
     auto buffer = create_double_seq_mbuffer<WRec>(n, false);
-    auto wss = Shard(buffer);
+    auto alias = Shard(buffer);
 
     for (size_t i=0; i<n; i++) {
         WRec r;
@@ -109,7 +110,7 @@ START_TEST(t_point_lookup)
         r.key = rec->rec.key;
         r.value = rec->rec.value;
 
-        auto result = wss.point_lookup(r);
+        auto result = alias.point_lookup(r);
         ck_assert_ptr_nonnull(result);
         ck_assert_int_eq(result->rec.key, r.key);
         ck_assert_int_eq(result->rec.value, r.value);
@@ -125,14 +126,14 @@ START_TEST(t_point_lookup_miss)
     size_t n = 10000;
 
     auto buffer = create_double_seq_mbuffer<WRec>(n, false);
-    auto wss = Shard(buffer);
+    auto alias = Shard(buffer);
 
     for (size_t i=n + 100; i<2*n; i++) {
         WRec r;
         r.key = i;
         r.value = i;
 
-        auto result = wss.point_lookup(r);
+        auto result = alias.point_lookup(r);
         ck_assert_ptr_null(result);
     }
 
@@ -169,7 +170,7 @@ START_TEST(t_full_cancelation)
 END_TEST
 
 
-START_TEST(t_wss_query)
+START_TEST(t_alias_query)
 {
     size_t n=1000;
     auto buffer = create_weighted_mbuffer<WRec>(n);
@@ -179,15 +180,15 @@ START_TEST(t_wss_query)
     size_t k = 1000;
 
     size_t cnt[3] = {0};
-    wss_query_parms<WRec> parms = {k};
+    wss::Parms<WRec> parms = {k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t total_samples = 0;
 
     for (size_t i=0; i<1000; i++) {
-        auto state = WSSQuery<WRec>::get_query_state(shard, &parms);
-        ((WSSState<WRec> *) state)->sample_size = k;
-        auto result = WSSQuery<WRec>::query(shard, state, &parms);
+        auto state = wss::Query<Shard, WRec>::get_query_state(shard, &parms);
+        ((wss::State<WRec> *) state)->sample_size = k;
+        auto result = wss::Query<Shard, WRec>::query(shard, state, &parms);
 
         total_samples += result.size();
 
@@ -195,7 +196,7 @@ START_TEST(t_wss_query)
             cnt[result[j].rec.key - 1]++;
         }
 
-        WSSQuery<WRec>::delete_query_state(state);
+        wss::Query<Shard, WRec>::delete_query_state(state);
     }
 
     ck_assert(roughly_equal(cnt[0], (double) total_samples/4.0, total_samples, .05));
@@ -209,7 +210,7 @@ START_TEST(t_wss_query)
 END_TEST
 
 
-START_TEST(t_wss_query_merge)
+START_TEST(t_alias_query_merge)
 {
     size_t n=1000;
     auto buffer = create_weighted_mbuffer<WRec>(n);
@@ -222,25 +223,25 @@ START_TEST(t_wss_query_merge)
     size_t k = 1000;
 
     size_t cnt[3] = {0};
-    wss_query_parms<WRec> parms = {k};
+    wss::Parms<WRec> parms = {k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     std::vector<std::vector<Wrapped<WRec>>> results(2);
 
     for (size_t i=0; i<1000; i++) {
-        auto state1 = WSSQuery<WRec>::get_query_state(shard, &parms);
-        ((WSSState<WRec> *) state1)->sample_size = k;
-        results[0] = WSSQuery<WRec>::query(shard, state1, &parms);
+        auto state1 = wss::Query<Shard, WRec>::get_query_state(shard, &parms);
+        ((wss::State<WRec> *) state1)->sample_size = k;
+        results[0] = wss::Query<Shard, WRec>::query(shard, state1, &parms);
 
-        auto state2 = WSSQuery<WRec>::get_query_state(shard, &parms);
-        ((WSSState<WRec> *) state2)->sample_size = k;
-        results[1] = WSSQuery<WRec>::query(shard, state2, &parms);
+        auto state2 = wss::Query<Shard, WRec>::get_query_state(shard, &parms);
+        ((wss::State<WRec> *) state2)->sample_size = k;
+        results[1] = wss::Query<Shard, WRec>::query(shard, state2, &parms);
 
-        WSSQuery<WRec>::delete_query_state(state1);
-        WSSQuery<WRec>::delete_query_state(state2);
+        wss::Query<Shard, WRec>::delete_query_state(state1);
+        wss::Query<Shard, WRec>::delete_query_state(state2);
     }
 
-    auto merged = WSSQuery<WRec>::merge(results, nullptr);
+    auto merged = wss::Query<Shard, WRec>::merge(results, nullptr);
 
     ck_assert_int_eq(merged.size(), 2*k);
     for (size_t i=0; i<merged.size(); i++) {
@@ -255,7 +256,7 @@ START_TEST(t_wss_query_merge)
 END_TEST
 
 
-START_TEST(t_wss_buffer_query_scan)
+START_TEST(t_alias_buffer_query_scan)
 {
     size_t n=1000;
     auto buffer = create_weighted_mbuffer<WRec>(n);
@@ -266,22 +267,22 @@ START_TEST(t_wss_buffer_query_scan)
     size_t k = 1000;
 
     size_t cnt[3] = {0};
-    wss_query_parms<WRec> parms = {k};
+    wss::Parms<WRec> parms = {k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t total_samples = 0;
 
     for (size_t i=0; i<1000; i++) {
-        auto state = WSSQuery<WRec, false>::get_buffer_query_state(buffer, &parms);
-        ((WSSBufferState<WRec> *) state)->sample_size = k;
-        auto result = WSSQuery<WRec, false>::buffer_query(buffer, state, &parms);
+        auto state = wss::Query<Shard, WRec, false>::get_buffer_query_state(buffer, &parms);
+        ((wss::BufferState<WRec> *) state)->sample_size = k;
+        auto result = wss::Query<Shard, WRec, false>::buffer_query(buffer, state, &parms);
         total_samples += result.size();
 
         for (size_t j=0; j<result.size(); j++) {
             cnt[result[j].rec.key - 1]++;
         }
 
-        WSSQuery<WRec, false>::delete_buffer_query_state(state);
+        wss::Query<Shard, WRec, false>::delete_buffer_query_state(state);
     }
 
     ck_assert(roughly_equal(cnt[0], (double) total_samples/4.0, total_samples, .05));
@@ -294,7 +295,7 @@ START_TEST(t_wss_buffer_query_scan)
 END_TEST
 
 
-START_TEST(t_wss_buffer_query_rejection)
+START_TEST(t_alias_buffer_query_rejection)
 {
     size_t n=1000;
     auto buffer = create_weighted_mbuffer<WRec>(n);
@@ -305,15 +306,15 @@ START_TEST(t_wss_buffer_query_rejection)
     size_t k = 1000;
 
     size_t cnt[3] = {0};
-    wss_query_parms<WRec> parms = {k};
+    wss::Parms<WRec> parms = {k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t total_samples = 0;
 
     for (size_t i=0; i<1000; i++) {
-        auto state = WSSQuery<WRec>::get_buffer_query_state(buffer, &parms);
-        ((WSSBufferState<WRec> *) state)->sample_size = k;
-        auto result = WSSQuery<WRec>::buffer_query(buffer, state, &parms);
+        auto state = wss::Query<Shard, WRec>::get_buffer_query_state(buffer, &parms);
+        ((wss::BufferState<WRec> *) state)->sample_size = k;
+        auto result = wss::Query<Shard, WRec>::buffer_query(buffer, state, &parms);
 
         total_samples += result.size();
 
@@ -321,7 +322,7 @@ START_TEST(t_wss_buffer_query_rejection)
             cnt[result[j].rec.key - 1]++;
         }
 
-        WSSQuery<WRec>::delete_buffer_query_state(state);
+        wss::Query<Shard, WRec>::delete_buffer_query_state(state);
     }
 
     ck_assert(roughly_equal(cnt[0], (double) total_samples/4.0, total_samples, .1));
@@ -336,32 +337,32 @@ END_TEST
 
 Suite *unit_testing()
 {
-    Suite *unit = suite_create("WSS Shard Unit Testing");
+    Suite *unit = suite_create("Alias Shard Unit Testing");
 
-    TCase *create = tcase_create("de::WSS constructor Testing");
+    TCase *create = tcase_create("de::Alias constructor Testing");
     tcase_add_test(create, t_mbuffer_init);
-    tcase_add_test(create, t_wss_init);
+    tcase_add_test(create, t_alias_init);
     tcase_set_timeout(create, 100);
     suite_add_tcase(unit, create);
 
 
-    TCase *tombstone = tcase_create("de:WSS::tombstone cancellation Testing");
+    TCase *tombstone = tcase_create("de:Alias::tombstone cancellation Testing");
     tcase_add_test(tombstone, t_full_cancelation);
     suite_add_tcase(unit, tombstone);
 
 
-    TCase *lookup = tcase_create("de:WSS:point_lookup Testing");
+    TCase *lookup = tcase_create("de:Alias:point_lookup Testing");
     tcase_add_test(lookup, t_point_lookup);
     tcase_add_test(lookup, t_point_lookup_miss);
     suite_add_tcase(unit, lookup);
 
 
 
-    TCase *sampling = tcase_create("de:WSS::WSSQuery Testing");
-    tcase_add_test(sampling, t_wss_query);
-    tcase_add_test(sampling, t_wss_query_merge);
-    tcase_add_test(sampling, t_wss_buffer_query_rejection);
-    tcase_add_test(sampling, t_wss_buffer_query_scan);
+    TCase *sampling = tcase_create("de:Alias::AliasQuery Testing");
+    tcase_add_test(sampling, t_alias_query);
+    tcase_add_test(sampling, t_alias_query_merge);
+    tcase_add_test(sampling, t_alias_buffer_query_rejection);
+    tcase_add_test(sampling, t_alias_buffer_query_scan);
     suite_add_tcase(unit, sampling);
 
     return unit;
diff --git a/tests/wirs_tests.cpp b/tests/augbtree_tests.cpp
index a72f950..878af82 100644
--- a/tests/wirs_tests.cpp
+++ b/tests/augbtree_tests.cpp
@@ -1,7 +1,7 @@
 /*
  * tests/wirs_tests.cpp
  *
- * Unit tests for WIRS (Augmented B+Tree) shard
+ * Unit tests for AugBTree (Augmented B+Tree) shard
  *
  * Copyright (C) 2023 Douglas Rumbaugh <drumbaugh@psu.edu> 
  *                    Dong Xie <dongx@psu.edu>
@@ -10,14 +10,15 @@
  *
  */
 
-#include "shard/WIRS.h"
+#include "shard/AugBTree.h"
+#include "query/wirs.h"
 #include "testing.h"
 
 #include <check.h>
 
 using namespace de;
 
-typedef WIRS<WRec> Shard;
+typedef AugBTree<WRec> Shard;
 
 START_TEST(t_mbuffer_init)
 {
@@ -183,15 +184,15 @@ START_TEST(t_wirs_query)
     size_t k = 1000;
 
     size_t cnt[3] = {0};
-    wirs_query_parms<WRec> parms = {lower_key, upper_key, k};
+    wirs::Parms<WRec> parms = {lower_key, upper_key, k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t total_samples = 0;
 
     for (size_t i=0; i<1000; i++) {
-        auto state = WIRSQuery<WRec>::get_query_state(shard, &parms);
-        ((WIRSState<WRec> *) state)->sample_size = k;
-        auto result = WIRSQuery<WRec>::query(shard, state, &parms);
+        auto state = wirs::Query<Shard, WRec>::get_query_state(shard, &parms);
+        ((wirs::State<WRec> *) state)->sample_size = k;
+        auto result = wirs::Query<Shard, WRec>::query(shard, state, &parms);
 
         total_samples += result.size();
 
@@ -199,7 +200,7 @@ START_TEST(t_wirs_query)
             cnt[result[j].rec.key - 1]++;
         }
 
-        WIRSQuery<WRec>::delete_query_state(state);
+        wirs::Query<Shard, WRec>::delete_query_state(state);
     }
 
     ck_assert(roughly_equal(cnt[0], (double) total_samples/4.0, total_samples, .05));
@@ -226,25 +227,25 @@ START_TEST(t_wirs_query_merge)
     size_t k = 1000;
 
     size_t cnt[3] = {0};
-    wirs_query_parms<WRec> parms = {lower_key, upper_key, k};
+    wirs::Parms<WRec> parms = {lower_key, upper_key, k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     std::vector<std::vector<Wrapped<WRec>>> results(2);
 
     for (size_t i=0; i<1000; i++) {
-        auto state1 = WIRSQuery<WRec>::get_query_state(shard, &parms);
-        ((WIRSState<WRec> *) state1)->sample_size = k;
-        results[0] = WIRSQuery<WRec>::query(shard, state1, &parms);
+        auto state1 = wirs::Query<Shard, WRec>::get_query_state(shard, &parms);
+        ((wirs::State<WRec> *) state1)->sample_size = k;
+        results[0] = wirs::Query<Shard, WRec>::query(shard, state1, &parms);
 
-        auto state2 = WIRSQuery<WRec>::get_query_state(shard, &parms);
-        ((WIRSState<WRec> *) state2)->sample_size = k;
-        results[1] = WIRSQuery<WRec>::query(shard, state2, &parms);
+        auto state2 = wirs::Query<Shard, WRec>::get_query_state(shard, &parms);
+        ((wirs::State<WRec> *) state2)->sample_size = k;
+        results[1] = wirs::Query<Shard, WRec>::query(shard, state2, &parms);
 
-        WIRSQuery<WRec>::delete_query_state(state1);
-        WIRSQuery<WRec>::delete_query_state(state2);
+        wirs::Query<Shard, WRec>::delete_query_state(state1);
+        wirs::Query<Shard, WRec>::delete_query_state(state2);
     }
 
-    auto merged = WIRSQuery<WRec>::merge(results, nullptr);
+    auto merged = wirs::Query<Shard, WRec>::merge(results, nullptr);
 
     ck_assert_int_eq(merged.size(), 2*k);
     for (size_t i=0; i<merged.size(); i++) {
@@ -270,15 +271,15 @@ START_TEST(t_wirs_buffer_query_scan)
     size_t k = 1000;
 
     size_t cnt[3] = {0};
-    wirs_query_parms<WRec> parms = {lower_key, upper_key, k};
+    wirs::Parms<WRec> parms = {lower_key, upper_key, k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t total_samples = 0;
 
     for (size_t i=0; i<1000; i++) {
-        auto state = WIRSQuery<WRec, false>::get_buffer_query_state(buffer, &parms);
-        ((WIRSBufferState<WRec> *) state)->sample_size = k;
-        auto result = WIRSQuery<WRec, false>::buffer_query(buffer, state, &parms);
+        auto state = wirs::Query<Shard, WRec, false>::get_buffer_query_state(buffer, &parms);
+        ((wirs::BufferState<WRec> *) state)->sample_size = k;
+        auto result = wirs::Query<Shard, WRec, false>::buffer_query(buffer, state, &parms);
 
         total_samples += result.size();
 
@@ -286,7 +287,7 @@ START_TEST(t_wirs_buffer_query_scan)
             cnt[result[j].rec.key - 1]++;
         }
 
-        WIRSQuery<WRec, false>::delete_buffer_query_state(state);
+        wirs::Query<Shard, WRec, false>::delete_buffer_query_state(state);
     }
 
     ck_assert(roughly_equal(cnt[0], (double) total_samples/4.0, total_samples, .05));
@@ -310,15 +311,15 @@ START_TEST(t_wirs_buffer_query_rejection)
     size_t k = 1000;
 
     size_t cnt[3] = {0};
-    wirs_query_parms<WRec> parms = {lower_key, upper_key, k};
+    wirs::Parms<WRec> parms = {lower_key, upper_key, k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t total_samples = 0;
 
     for (size_t i=0; i<1000; i++) {
-        auto state = WIRSQuery<WRec>::get_buffer_query_state(buffer, &parms);
-        ((WIRSBufferState<WRec> *) state)->sample_size = k;
-        auto result = WIRSQuery<WRec>::buffer_query(buffer, state, &parms);
+        auto state = wirs::Query<Shard, WRec>::get_buffer_query_state(buffer, &parms);
+        ((wirs::BufferState<WRec> *) state)->sample_size = k;
+        auto result = wirs::Query<Shard, WRec>::buffer_query(buffer, state, &parms);
 
         total_samples += result.size();
 
@@ -326,7 +327,7 @@ START_TEST(t_wirs_buffer_query_rejection)
             cnt[result[j].rec.key - 1]++;
         }
 
-        WIRSQuery<WRec>::delete_buffer_query_state(state);
+        wirs::Query<Shard, WRec>::delete_buffer_query_state(state);
     }
 
     ck_assert(roughly_equal(cnt[0], (double) total_samples/4.0, total_samples, .05));
@@ -341,27 +342,27 @@ END_TEST
 
 Suite *unit_testing()
 {
-    Suite *unit = suite_create("WIRS Shard Unit Testing");
+    Suite *unit = suite_create("AugBTree Shard Unit Testing");
 
-    TCase *create = tcase_create("de::WIRS constructor Testing");
+    TCase *create = tcase_create("de::AugBTree constructor Testing");
     tcase_add_test(create, t_mbuffer_init);
     tcase_add_test(create, t_wirs_init);
     tcase_set_timeout(create, 100);
     suite_add_tcase(unit, create);
 
 
-    TCase *tombstone = tcase_create("de:WIRS::tombstone cancellation Testing");
+    TCase *tombstone = tcase_create("de:AugBTree::tombstone cancellation Testing");
     tcase_add_test(tombstone, t_full_cancelation);
     suite_add_tcase(unit, tombstone);
 
 
-    TCase *lookup = tcase_create("de:WIRS:point_lookup Testing");
+    TCase *lookup = tcase_create("de:AugBTree:point_lookup Testing");
     tcase_add_test(lookup, t_point_lookup);
     tcase_add_test(lookup, t_point_lookup_miss);
     suite_add_tcase(unit, lookup);
 
 
-    TCase *sampling = tcase_create("de:WIRS::WIRSQuery Testing");
+    TCase *sampling = tcase_create("de:AugBTree::AugBTreeQuery Testing");
     tcase_add_test(sampling, t_wirs_query);
     tcase_add_test(sampling, t_wirs_query_merge);
     tcase_add_test(sampling, t_wirs_buffer_query_rejection);
diff --git a/tests/de_level_tag.cpp b/tests/de_level_tag.cpp
index 822ccc2..f3f099d 100644
--- a/tests/de_level_tag.cpp
+++ b/tests/de_level_tag.cpp
@@ -15,11 +15,12 @@
 
 #include "testing.h"
 #include "framework/DynamicExtension.h"
-#include "shard/WIRS.h"
+#include "shard/ISAMTree.h"
+#include "query/rangequery.h"
 
 #include <check.h>
 using namespace de;
 
-typedef DynamicExtension<WRec, WIRS<WRec>, WIRSQuery<WRec>, LayoutPolicy::LEVELING, DeletePolicy::TAGGING, SerialScheduler> DE;
+typedef DynamicExtension<Rec, ISAMTree<Rec>, rq::Query<ISAMTree<Rec>, Rec>, LayoutPolicy::LEVELING, DeletePolicy::TAGGING, SerialScheduler> DE;
 
 #include "dynamic_extension_tests.inc"
diff --git a/tests/de_level_tomb.cpp b/tests/de_level_tomb.cpp
index ba3f784..912743c 100644
--- a/tests/de_level_tomb.cpp
+++ b/tests/de_level_tomb.cpp
@@ -15,11 +15,12 @@
 
 #include "testing.h"
 #include "framework/DynamicExtension.h"
-#include "shard/WIRS.h"
+#include "shard/ISAMTree.h"
+#include "query/rangequery.h"
 
 #include <check.h>
 using namespace de;
 
-typedef DynamicExtension<WRec, WIRS<WRec>, WIRSQuery<WRec>, LayoutPolicy::LEVELING, DeletePolicy::TOMBSTONE, FIFOScheduler> DE;
+typedef DynamicExtension<Rec, ISAMTree<Rec>, rq::Query<ISAMTree<Rec>, Rec>, LayoutPolicy::LEVELING, DeletePolicy::TOMBSTONE, SerialScheduler> DE;
 
 #include "dynamic_extension_tests.inc"
diff --git a/tests/de_tier_tag.cpp b/tests/de_tier_tag.cpp
index 2c263eb..712c203 100644
--- a/tests/de_tier_tag.cpp
+++ b/tests/de_tier_tag.cpp
@@ -16,11 +16,12 @@
 #include "testing.h"
 #include "framework/DynamicExtension.h"
 #include "framework/scheduling/SerialScheduler.h"
-#include "shard/WIRS.h"
+#include "shard/ISAMTree.h"
+#include "query/rangequery.h"
 
 #include <check.h>
 using namespace de;
 
-typedef DynamicExtension<WRec, WIRS<WRec>, WIRSQuery<WRec>, LayoutPolicy::TEIRING, DeletePolicy::TAGGING, SerialScheduler> DE;
+typedef DynamicExtension<Rec, ISAMTree<Rec>, rq::Query<ISAMTree<Rec>, Rec>, LayoutPolicy::TEIRING, DeletePolicy::TAGGING, SerialScheduler> DE;
 
 #include "dynamic_extension_tests.inc"
diff --git a/tests/de_tier_tomb.cpp b/tests/de_tier_tomb.cpp
index 509494a..f25ec34 100644
--- a/tests/de_tier_tomb.cpp
+++ b/tests/de_tier_tomb.cpp
@@ -15,11 +15,12 @@
 
 #include "testing.h"
 #include "framework/DynamicExtension.h"
-#include "shard/WIRS.h"
+#include "shard/ISAMTree.h"
+#include "query/rangequery.h"
 
 #include <check.h>
 using namespace de;
 
-typedef DynamicExtension<WRec, WIRS<WRec>, WIRSQuery<WRec>, LayoutPolicy::TEIRING, DeletePolicy::TOMBSTONE, SerialScheduler> DE;
+typedef DynamicExtension<Rec, ISAMTree<Rec>, rq::Query<ISAMTree<Rec>, Rec>, LayoutPolicy::TEIRING, DeletePolicy::TOMBSTONE, SerialScheduler> DE;
 
 #include "dynamic_extension_tests.inc"
diff --git a/tests/dynamic_extension_tests.inc b/tests/dynamic_extension_tests.inc
index df88d98..bcb5ae6 100644
--- a/tests/dynamic_extension_tests.inc
+++ b/tests/dynamic_extension_tests.inc
@@ -12,77 +12,76 @@
 
 START_TEST(t_create)
 {
-    auto ext_wirs = new DE(100, 2, 1);
+    auto test_de = new DE(100, 2, 1);
 
+    ck_assert_ptr_nonnull(test_de);
+    ck_assert_int_eq(test_de->get_record_count(), 0);
+    ck_assert_int_eq(test_de->get_height(), 0);
 
-    ck_assert_ptr_nonnull(ext_wirs);
-    ck_assert_int_eq(ext_wirs->get_record_count(), 0);
-    ck_assert_int_eq(ext_wirs->get_height(), 0);
-
-    delete ext_wirs;
+    delete test_de;
 }
 END_TEST
 
 
 START_TEST(t_insert)
 {
-    auto ext_wirs = new DE(100, 2, 1);
+    auto test_de = new DE(100, 2, 1);
 
     uint64_t key = 0;
     uint32_t val = 0;
     for (size_t i=0; i<100; i++) {
-        WRec r = {key, val, 1};
-        ck_assert_int_eq(ext_wirs->insert(r), 1);
+        Rec r = {key, val};
+        ck_assert_int_eq(test_de->insert(r), 1);
         key++;
         val++;
     }
 
-    ck_assert_int_eq(ext_wirs->get_height(), 0);
-    ck_assert_int_eq(ext_wirs->get_record_count(), 100);
+    ck_assert_int_eq(test_de->get_height(), 0);
+    ck_assert_int_eq(test_de->get_record_count(), 100);
 
-    delete ext_wirs;
+    delete test_de;
 }
 END_TEST
 
 
 START_TEST(t_debug_insert)
 {
-    auto ext_wirs = new DE(100, 2, 1);
+    auto test_de = new DE(100, 2, 1);
 
     uint64_t key = 0;
     uint32_t val = 0;
     for (size_t i=0; i<1000; i++) {
-        WRec r = {key, val, 1};
-        ck_assert_int_eq(ext_wirs->insert(r), 1);
-        ck_assert_int_eq(ext_wirs->get_record_count(), i+1);
+        Rec r = {key, val};
+        ck_assert_int_eq(test_de->insert(r), 1);
+        ck_assert_int_eq(test_de->get_record_count(), i+1);
         key++;
         val++;
     }
 
-    delete ext_wirs;
+    delete test_de;
 }
 END_TEST
 
 
 START_TEST(t_insert_with_mem_merges)
 {
-    auto ext_wirs = new DE(100, 2, 1);
+    auto test_de = new DE(100, 2, 1);
 
     uint64_t key = 0;
     uint32_t val = 0;
     for (size_t i=0; i<300; i++) {
-        WRec r = {key, val, 1};
-        ck_assert_int_eq(ext_wirs->insert(r), 1);
+        Rec r = {key, val};
+        ck_assert_int_eq(test_de->insert(r), 1);
         key++;
         val++;
     }
 
-    ext_wirs->await_next_epoch();
+    test_de->await_next_epoch();
 
-    ck_assert_int_eq(ext_wirs->get_record_count(), 300);
-    ck_assert_int_eq(ext_wirs->get_height(), 1);
+    ck_assert_int_eq(test_de->get_record_count(), 300);
+    ck_assert_int_eq(test_de->get_height(), 1);
 
-    delete ext_wirs;
+    delete test_de;
 }
 END_TEST
 
@@ -90,13 +89,13 @@ END_TEST
 /*
 START_TEST(t_range_sample_memtable)
 {
-    auto ext_wirs = new DE(100, 2, 1);
+    auto test_de = new DE(100, 2, 1);
 
     uint64_t key = 0;
     uint32_t val = 0;
     for (size_t i=0; i<100; i++) {
-        WRec r = {key, val, 1};
-        ck_assert_int_eq(ext_wirs->insert(r), 1);
+        Rec r = {key, val};
+        ck_assert_int_eq(test_de->insert(r), 1);
         key++;
         val++;
     }
@@ -106,9 +105,9 @@ START_TEST(t_range_sample_memtable)
 
     char *buf = (char *) std::aligned_alloc(SECTOR_SIZE, PAGE_SIZE);
     char *util_buf = (char *) std::aligned_alloc(SECTOR_SIZE, PAGE_SIZE);
-    WRec sample_set[100];
+    Rec sample_set[100];
 
-    ext_wirs->range_sample(sample_set, lower_bound, upper_bound, 100);
+    test_de->range_sample(sample_set, lower_bound, upper_bound, 100);
 
     for(size_t i=0; i<100; i++) {
         ck_assert_int_le(sample_set[i].key, upper_bound);
@@ -118,20 +117,20 @@ START_TEST(t_range_sample_memtable)
     free(buf);
     free(util_buf);
 
-    delete ext_wirs;
+    delete test_de;
 }
 END_TEST
 
 
 START_TEST(t_range_sample_memlevels)
 {
-    auto ext_wirs = new DE(100, 2, 1);
+    auto test_de = new DE(100, 2, 1);
 
     uint64_t key = 0;
     uint32_t val = 0;
     for (size_t i=0; i<300; i++) {
-        WRec r = {key, val, 1};
-        ck_assert_int_eq(ext_wirs->insert(r), 1);
+        Rec r = {key, val};
+        ck_assert_int_eq(test_de->insert(r), 1);
         key++;
         val++;
     }
@@ -142,8 +141,8 @@ START_TEST(t_range_sample_memlevels)
     char *buf = (char *) std::aligned_alloc(SECTOR_SIZE, PAGE_SIZE);
     char *util_buf = (char *) std::aligned_alloc(SECTOR_SIZE, PAGE_SIZE);
 
-    WRec sample_set[100];
-    ext_wirs->range_sample(sample_set, lower_bound, upper_bound, 100);
+    Rec sample_set[100];
+    test_de->range_sample(sample_set, lower_bound, upper_bound, 100);
 
     for(size_t i=0; i<100; i++) {
         ck_assert_int_le(sample_set[i].key, upper_bound);
@@ -153,33 +152,19 @@ START_TEST(t_range_sample_memlevels)
     free(buf);
     free(util_buf);
 
-    delete ext_wirs;
+    delete test_de;
 }
 END_TEST
 */
 
-START_TEST(t_range_sample_weighted)
+START_TEST(t_range_query)
 {
-    auto ext_wirs = new DE(100, 2, 1);
+    auto test_de = new DE(100, 2, 1);
     size_t n = 10000;
 
     std::vector<uint64_t> keys;
-
-    uint64_t key = 1;
-    for (size_t i=0; i< n / 2; i++) {
-        keys.push_back(key);
-    }
-
-    // put in a quarter of the count with weight two.
-    key = 2;
-    for (size_t i=0; i< n / 4; i++) {
-        keys.push_back(key);
-    }
-
-    // the remaining quarter with weight four.
-    key = 3;
-    for (size_t i=0; i< n / 4; i++) {
-        keys.push_back(key);
+    for (size_t i=0; i<n; i++) {
+        keys.push_back(rand() % 25000);
     }
 
     std::random_device rd;
@@ -187,51 +172,33 @@ START_TEST(t_range_sample_weighted)
     std::shuffle(keys.begin(), keys.end(), gen);
 
     for (size_t i=0; i<keys.size(); i++) {
-        uint64_t weight;
-        if (keys[i] == 1)  {
-            weight = 2;
-        } else if (keys[i] == 2) {
-            weight = 4;
-        } else {
-            weight = 8;
-        }
-
-        WRec r = {keys[i], (uint32_t) i, weight};
-        ext_wirs->insert(r);
+        Rec r = {keys[i], (uint32_t) i};
+        ck_assert_int_eq(test_de->insert(r), 1);
     }
 
-    ext_wirs->await_next_epoch();
+    test_de->await_next_epoch();
 
-    size_t k = 1000;
-    uint64_t lower_key = 0;
-    uint64_t upper_key = 5;
+    std::sort(keys.begin(), keys.end());
 
-    size_t cnt[3] = {0};
-    size_t total_samples = 0;
+    auto idx = rand() % (keys.size() - 250);
 
-    wirs_query_parms<WRec> p;
+    uint64_t lower_key = keys[idx];
+    uint64_t upper_key = keys[idx + 250];
+
+    rq::Parms<Rec> p;
     p.lower_bound = lower_key;
     p.upper_bound = upper_key;
-    p.sample_size = k;
-    p.rng = gsl_rng_alloc(gsl_rng_mt19937);
-
-    for (size_t i=0; i<1000; i++) {
 
-        auto result = ext_wirs->query(&p);
-        auto r = result.get();
-        total_samples += r.size();
+    auto result = test_de->query(&p);
+    auto r = result.get();
+    std::sort(r.begin(), r.end());
+    ck_assert_int_eq(r.size(), 251);
 
-        for (size_t j=0; j<r.size(); j++) {
-            cnt[r[j].key - 1]++;
-        }
+    for (size_t i=0; i<r.size(); i++) {
+        ck_assert_int_eq(r[i].key, keys[idx + i]);
     }
 
-    ck_assert(roughly_equal(cnt[0], (double) total_samples/4.0, total_samples, .03));
-    ck_assert(roughly_equal(cnt[1], (double) total_samples/4.0, total_samples, .03));
-    ck_assert(roughly_equal(cnt[2], (double) total_samples/2.0, total_samples, .03));
-
-    gsl_rng_free(p.rng);
-    delete ext_wirs;
+    delete test_de;
 }
 END_TEST
 
@@ -239,7 +206,7 @@ END_TEST
 START_TEST(t_tombstone_merging_01)
 {
     size_t reccnt = 100000;
-    auto ext_wirs = new DE(100, 2, .01);
+    auto test_de = new DE(100, 2, .01);
 
     auto rng = gsl_rng_alloc(gsl_rng_mt19937);
 
@@ -259,16 +226,16 @@ START_TEST(t_tombstone_merging_01)
     size_t deletes = 0;
     size_t cnt=0;
     for (auto rec : records) {
-        WRec r = {rec.first, rec.second, 1};
-        ck_assert_int_eq(ext_wirs->insert(r), 1);
+        Rec r = {rec.first, rec.second};
+        ck_assert_int_eq(test_de->insert(r), 1);
 
          if (gsl_rng_uniform(rng) < 0.05 && !to_delete.empty()) {
             std::vector<std::pair<uint64_t, uint32_t>> del_vec;
             std::sample(to_delete.begin(), to_delete.end(), std::back_inserter(del_vec), 3, std::mt19937{std::random_device{}()});
 
             for (size_t i=0; i<del_vec.size(); i++) {
-                WRec dr = {del_vec[i].first, del_vec[i].second, 1};
-                ext_wirs->erase(dr);
+                Rec dr = {del_vec[i].first, del_vec[i].second};
+                test_de->erase(dr);
                 deletes++;
                 to_delete.erase(del_vec[i]);
                 deleted.insert(del_vec[i]);
@@ -279,26 +246,26 @@ START_TEST(t_tombstone_merging_01)
             to_delete.insert(rec);
         }
 
-        ck_assert(ext_wirs->validate_tombstone_proportion());
+        ck_assert(test_de->validate_tombstone_proportion());
     }
 
-    ext_wirs->await_next_epoch();
+    test_de->await_next_epoch();
 
-    ck_assert(ext_wirs->validate_tombstone_proportion());
+    ck_assert(test_de->validate_tombstone_proportion());
 
     gsl_rng_free(rng);
-    delete ext_wirs;
+    delete test_de;
 }
 END_TEST
 
 DE *create_test_tree(size_t reccnt, size_t memlevel_cnt) {
     auto rng = gsl_rng_alloc(gsl_rng_mt19937);
 
-    auto ext_wirs = new DE(1000, 2, 1);
+    auto test_de = new DE(1000, 2, 1);
 
-    std::set<WRec> records; 
-    std::set<WRec> to_delete;
-    std::set<WRec> deleted;
+    std::set<Rec> records; 
+    std::set<Rec> to_delete;
+    std::set<Rec> deleted;
 
     while (records.size() < reccnt) {
         uint64_t key = rand();
@@ -311,14 +278,14 @@ DE *create_test_tree(size_t reccnt, size_t memlevel_cnt) {
 
     size_t deletes = 0;
     for (auto rec : records) {
-        ck_assert_int_eq(ext_wirs->insert(rec), 1);
+        ck_assert_int_eq(test_de->insert(rec), 1);
 
          if (gsl_rng_uniform(rng) < 0.05 && !to_delete.empty()) {
-            std::vector<WRec> del_vec;
+            std::vector<Rec> del_vec;
             std::sample(to_delete.begin(), to_delete.end(), std::back_inserter(del_vec), 3, std::mt19937{std::random_device{}()});
 
             for (size_t i=0; i<del_vec.size(); i++) {
-                ext_wirs->erase(del_vec[i]);
+                test_de->erase(del_vec[i]);
                 deletes++;
                 to_delete.erase(del_vec[i]);
                 deleted.insert(del_vec[i]);
@@ -332,7 +299,7 @@ DE *create_test_tree(size_t reccnt, size_t memlevel_cnt) {
 
     gsl_rng_free(rng);
 
-    return ext_wirs;
+    return test_de;
 }
 
 START_TEST(t_static_structure)
@@ -340,11 +307,11 @@ START_TEST(t_static_structure)
     auto rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t reccnt = 100000;
-    auto ext_wirs = new DE(100, 2, 1);
+    auto test_de = new DE(100, 2, 1);
 
-    std::set<WRec> records; 
-    std::set<WRec> to_delete;
-    std::set<WRec> deleted;
+    std::set<Rec> records; 
+    std::set<Rec> to_delete;
+    std::set<Rec> deleted;
 
     while (records.size() < reccnt) {
         uint64_t key = rand();
@@ -352,7 +319,7 @@ START_TEST(t_static_structure)
 
         if (records.find({key, val}) != records.end()) continue;
 
-        records.insert({key, val, 1});
+        records.insert({key, val});
     }
 
     size_t deletes = 0;
@@ -360,15 +327,15 @@ START_TEST(t_static_structure)
     size_t k=0;
     for (auto rec : records) {
         k++;
-        ck_assert_int_eq(ext_wirs->insert(rec), 1);
+        ck_assert_int_eq(test_de->insert(rec), 1);
         t_reccnt++;
 
          if (gsl_rng_uniform(rng) < 0.05 && !to_delete.empty()) {
-            std::vector<WRec> del_vec;
+            std::vector<Rec> del_vec;
             std::sample(to_delete.begin(), to_delete.end(), std::back_inserter(del_vec), 3, std::mt19937{std::random_device{}()});
 
             for (size_t i=0; i<del_vec.size(); i++) {
-                ck_assert_int_eq(ext_wirs->erase(del_vec[i]), 1);
+                ck_assert_int_eq(test_de->erase(del_vec[i]), 1);
 
                 deletes++;
                 to_delete.erase(del_vec[i]);
@@ -381,7 +348,7 @@ START_TEST(t_static_structure)
         }
     }
 
-    auto flat = ext_wirs->create_static_structure();
+    auto flat = test_de->create_static_structure();
     ck_assert_int_eq(flat->get_record_count(), reccnt - deletes);
 
     uint64_t prev_key = 0;
@@ -393,7 +360,7 @@ START_TEST(t_static_structure)
 
     gsl_rng_free(rng);
     delete flat;
-    delete ext_wirs;
+    delete test_de;
 }
 END_TEST
 
@@ -406,21 +373,15 @@ Suite *unit_testing()
     tcase_add_test(create, t_create);
     suite_add_tcase(unit, create);
 
-    TCase *insert = tcase_create("de::DynamicExtension<WIRS>::insert Testing");
+    TCase *insert = tcase_create("de::DynamicExtension<ISAMTree>::insert Testing");
     tcase_add_test(insert, t_insert);
     tcase_add_test(insert, t_insert_with_mem_merges);
     tcase_add_test(insert, t_debug_insert);
     suite_add_tcase(unit, insert);
 
-    TCase *sampling = tcase_create("de::DynamicExtension<WIRS>::range_sample Testing");
-
-    tcase_add_test(sampling, t_range_sample_weighted);
-    suite_add_tcase(unit, sampling);
-
-    /*
-    tcase_add_test(sampling, t_range_sample_memtable);
-    tcase_add_test(sampling, t_range_sample_memlevels);
-    */
+    TCase *query = tcase_create("de::DynamicExtension<ISAMTree>::range_query Testing");
+    tcase_add_test(query, t_range_query);
+    suite_add_tcase(unit, query);
 
     TCase *ts = tcase_create("de::DynamicExtension::tombstone_compaction Testing");
     tcase_add_test(ts, t_tombstone_merging_01);
diff --git a/tests/internal_level_tests.cpp b/tests/internal_level_tests.cpp
index 056e458..1009ea8 100644
--- a/tests/internal_level_tests.cpp
+++ b/tests/internal_level_tests.cpp
@@ -9,7 +9,8 @@
  * All rights reserved. Published under the Modified BSD License.
  *
  */
-#include "shard/WIRS.h"
+#include "shard/ISAMTree.h"
+#include "query/rangequery.h"
 #include "framework/structure/InternalLevel.h"
 #include "framework/interface/Record.h"
 #include "framework/interface/Query.h"
@@ -21,12 +22,12 @@
 
 using namespace de;
 
-typedef InternalLevel<WRec, WIRS<WRec>, WIRSQuery<WRec>> ILevel;
+typedef InternalLevel<Rec, ISAMTree<Rec>, rq::Query<ISAMTree<Rec>, Rec>> ILevel;
 
 START_TEST(t_memlevel_merge)
 {
-    auto tbl1 = create_test_mbuffer<WRec>(100);
-    auto tbl2 = create_test_mbuffer<WRec>(100);
+    auto tbl1 = create_test_mbuffer<Rec>(100);
+    auto tbl2 = create_test_mbuffer<Rec>(100);
 
     auto base_level = new ILevel(1, 1);
     base_level->append_buffer(tbl1);
@@ -48,8 +49,8 @@ START_TEST(t_memlevel_merge)
 
 
 ILevel *create_test_memlevel(size_t reccnt) {
-    auto tbl1 = create_test_mbuffer<WRec>(reccnt/2);
-    auto tbl2 = create_test_mbuffer<WRec>(reccnt/2);
+    auto tbl1 = create_test_mbuffer<Rec>(reccnt/2);
+    auto tbl2 = create_test_mbuffer<Rec>(reccnt/2);
 
     auto base_level = new ILevel(1, 2);
     base_level->append_buffer(tbl1); 
diff --git a/tests/memisam_tests.cpp b/tests/memisam_tests.cpp
index 0ae97dc..d3b8087 100644
--- a/tests/memisam_tests.cpp
+++ b/tests/memisam_tests.cpp
@@ -1,7 +1,7 @@
 /*
- * tests/irs_tests.cpp
+ * tests/isam_tests.cpp
  *
- * Unit tests for MemISAM (Augmented B+Tree) shard
+ * Unit tests for ISAM Tree shard
  *
  * Copyright (C) 2023 Douglas Rumbaugh <drumbaugh@psu.edu> 
  *                    Dong Xie <dongx@psu.edu>
@@ -10,14 +10,15 @@
  *
  */
 
-#include "shard/MemISAM.h"
+#include "shard/ISAMTree.h"
+#include "query/irs.h"
 #include "testing.h"
 
 #include <check.h>
 
 using namespace de;
 
-typedef MemISAM<Rec> Shard;
+typedef ISAMTree<Rec> Shard;
 
 START_TEST(t_mbuffer_init)
 {
@@ -181,15 +182,15 @@ START_TEST(t_irs_query)
     size_t k = 100;
 
     size_t cnt[3] = {0};
-    irs_query_parms<Rec> parms = {lower_key, upper_key, k};
+    irs::Parms<Rec> parms = {lower_key, upper_key, k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t total_samples = 0;
 
     for (size_t i=0; i<1000; i++) {
-        auto state = IRSQuery<Rec, false>::get_query_state(&isam, &parms);
-        ((IRSState<WRec> *) state)->sample_size = k;
-        auto result = IRSQuery<Rec, false>::query(&isam, state, &parms);
+        auto state = irs::Query<Shard, Rec, false>::get_query_state(&isam, &parms);
+        ((irs::State<WRec> *) state)->sample_size = k;
+        auto result = irs::Query<Shard, Rec, false>::query(&isam, state, &parms);
 
         ck_assert_int_eq(result.size(), k);
 
@@ -198,7 +199,7 @@ START_TEST(t_irs_query)
             ck_assert_int_ge(rec.rec.key, lower_key);
         }
 
-        IRSQuery<Rec, false>::delete_query_state(state);
+        irs::Query<Shard, Rec, false>::delete_query_state(state);
     }
 
     gsl_rng_free(parms.rng);
@@ -220,25 +221,25 @@ START_TEST(t_irs_query_merge)
     size_t k = 1000;
 
     size_t cnt[3] = {0};
-    irs_query_parms<Rec> parms = {lower_key, upper_key, k};
+    irs::Parms<Rec> parms = {lower_key, upper_key, k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     std::vector<std::vector<de::Wrapped<Rec>>> results(2);
 
     for (size_t i=0; i<1000; i++) {
-        auto state1 = IRSQuery<Rec>::get_query_state(&shard, &parms);
-        ((IRSState<WRec> *) state1)->sample_size = k;
-        results[0] = IRSQuery<Rec>::query(&shard, state1, &parms);
+        auto state1 = irs::Query<Shard, Rec>::get_query_state(&shard, &parms);
+        ((irs::State<WRec> *) state1)->sample_size = k;
+        results[0] = irs::Query<Shard, Rec>::query(&shard, state1, &parms);
 
-        auto state2 = IRSQuery<Rec>::get_query_state(&shard, &parms);
-        ((IRSState<WRec> *) state2)->sample_size = k;
-        results[1] = IRSQuery<Rec>::query(&shard, state2, &parms);
+        auto state2 = irs::Query<Shard, Rec>::get_query_state(&shard, &parms);
+        ((irs::State<WRec> *) state2)->sample_size = k;
+        results[1] = irs::Query<Shard, Rec>::query(&shard, state2, &parms);
 
-        IRSQuery<Rec>::delete_query_state(state1);
-        IRSQuery<Rec>::delete_query_state(state2);
+        irs::Query<Shard, Rec>::delete_query_state(state1);
+        irs::Query<Shard, Rec>::delete_query_state(state2);
     }
 
-    auto merged = IRSQuery<Rec>::merge(results, nullptr);
+    auto merged = irs::Query<Shard, Rec>::merge(results, nullptr);
 
     ck_assert_int_eq(merged.size(), 2*k);
     for (size_t i=0; i<merged.size(); i++) {
@@ -263,15 +264,15 @@ START_TEST(t_irs_buffer_query_scan)
     size_t k = 100;
 
     size_t cnt[3] = {0};
-    irs_query_parms<Rec> parms = {lower_key, upper_key, k};
+    irs::Parms<Rec> parms = {lower_key, upper_key, k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t total_samples = 0;
 
     for (size_t i=0; i<1000; i++) {
-        auto state = IRSQuery<Rec, false>::get_buffer_query_state(buffer, &parms);
-        ((IRSBufferState<WRec> *) state)->sample_size = k;
-        auto result = IRSQuery<Rec, false>::buffer_query(buffer, state, &parms);
+        auto state = irs::Query<Shard, Rec, false>::get_buffer_query_state(buffer, &parms);
+        ((irs::BufferState<WRec> *) state)->sample_size = k;
+        auto result = irs::Query<Shard, Rec, false>::buffer_query(buffer, state, &parms);
 
         ck_assert_int_eq(result.size(), k);
 
@@ -280,7 +281,7 @@ START_TEST(t_irs_buffer_query_scan)
             ck_assert_int_ge(rec.rec.key, lower_key);
         }
 
-        IRSQuery<Rec, false>::delete_buffer_query_state(state);
+        irs::Query<Shard, Rec, false>::delete_buffer_query_state(state);
     }
 
     gsl_rng_free(parms.rng);
@@ -300,15 +301,15 @@ START_TEST(t_irs_buffer_query_rejection)
     size_t k = 10000;
 
     size_t cnt[3] = {0};
-    irs_query_parms<Rec> parms = {lower_key, upper_key, k};
+    irs::Parms<Rec> parms = {lower_key, upper_key, k};
     parms.rng = gsl_rng_alloc(gsl_rng_mt19937);
 
     size_t total_samples = 0;
 
     for (size_t i=0; i<1000; i++) {
-        auto state = IRSQuery<Rec>::get_buffer_query_state(buffer, &parms);
-        ((IRSBufferState<WRec> *) state)->sample_size = k;
-        auto result = IRSQuery<Rec>::buffer_query(buffer, state, &parms);
+        auto state = irs::Query<Shard, Rec>::get_buffer_query_state(buffer, &parms);
+        ((irs::BufferState<WRec> *) state)->sample_size = k;
+        auto result = irs::Query<Shard, Rec>::buffer_query(buffer, state, &parms);
 
         ck_assert_int_gt(result.size(), 0);
         ck_assert_int_le(result.size(), k);
@@ -318,7 +319,7 @@ START_TEST(t_irs_buffer_query_rejection)
             ck_assert_int_ge(rec.rec.key, lower_key);
         }
 
-        IRSQuery<Rec>::delete_buffer_query_state(state);
+        irs::Query<Shard, Rec>::delete_buffer_query_state(state);
     }
 
     gsl_rng_free(parms.rng);
@@ -329,27 +330,27 @@ END_TEST
 
 Suite *unit_testing()
 {
-    Suite *unit = suite_create("MemISAM Shard Unit Testing");
+    Suite *unit = suite_create("ISAMTree Shard Unit Testing");
 
-    TCase *create = tcase_create("de::MemISAM constructor Testing");
+    TCase *create = tcase_create("de::ISAMTree constructor Testing");
     tcase_add_test(create, t_mbuffer_init);
     tcase_add_test(create, t_irs_init);
     tcase_set_timeout(create, 100);
     suite_add_tcase(unit, create);
 
 
-    TCase *tombstone = tcase_create("de:MemISAM::tombstone cancellation Testing");
+    TCase *tombstone = tcase_create("de:ISAMTree::tombstone cancellation Testing");
     tcase_add_test(tombstone, t_full_cancelation);
     suite_add_tcase(unit, tombstone);
 
 
-    TCase *lookup = tcase_create("de:MemISAM:point_lookup Testing");
+    TCase *lookup = tcase_create("de:ISAMTree:point_lookup Testing");
     tcase_add_test(lookup, t_point_lookup);
     tcase_add_test(lookup, t_point_lookup_miss);
     suite_add_tcase(unit, lookup);
 
 
-    TCase *sampling = tcase_create("de:MemISAM::MemISAMQuery Testing");
+    TCase *sampling = tcase_create("de:ISAMTree::ISAMTreeQuery Testing");
     tcase_add_test(sampling, t_irs_query);
     tcase_add_test(sampling, t_irs_query_merge);
     tcase_add_test(sampling, t_irs_buffer_query_rejection);
diff --git a/tests/pgm_tests.cpp b/tests/pgm_tests.cpp
index 0552417..1565384 100644
--- a/tests/pgm_tests.cpp
+++ b/tests/pgm_tests.cpp
@@ -11,6 +11,7 @@
  */
 
 #include "shard/PGM.h"
+#include "query/rangequery.h"
 #include "testing.h"
 
 #include <check.h>
@@ -144,13 +145,13 @@ START_TEST(t_range_query)
     auto buffer = create_sequential_mbuffer<Rec>(100, 1000);
     auto shard = Shard(buffer);
 
-    pgm_range_query_parms<Rec> parms;
+    rq::Parms<Rec> parms;
     parms.lower_bound = 300;
     parms.upper_bound = 500;
 
-    auto state = PGMRangeQuery<Rec>::get_query_state(&shard, &parms);
-    auto result = PGMRangeQuery<Rec>::query(&shard, state, &parms);
-    PGMRangeQuery<Rec>::delete_query_state(state);
+    auto state = rq::Query<Shard, Rec>::get_query_state(&shard, &parms);
+    auto result = rq::Query<Shard, Rec>::query(&shard, state, &parms);
+    rq::Query<Shard, Rec>::delete_query_state(state);
 
     ck_assert_int_eq(result.size(), parms.upper_bound - parms.lower_bound + 1);
     for (size_t i=0; i<result.size(); i++) {
@@ -167,13 +168,13 @@ START_TEST(t_buffer_range_query)
 {
     auto buffer = create_sequential_mbuffer<Rec>(100, 1000);
 
-    pgm_range_query_parms<Rec> parms;
+    rq::Parms<Rec> parms;
     parms.lower_bound = 300;
     parms.upper_bound = 500;
 
-    auto state = PGMRangeQuery<Rec>::get_buffer_query_state(buffer, &parms);
-    auto result = PGMRangeQuery<Rec>::buffer_query(buffer, state, &parms);
-    PGMRangeQuery<Rec>::delete_buffer_query_state(state);
+    auto state = rq::Query<Shard, Rec>::get_buffer_query_state(buffer, &parms);
+    auto result = rq::Query<Shard, Rec>::buffer_query(buffer, state, &parms);
+    rq::Query<Shard, Rec>::delete_buffer_query_state(state);
 
     ck_assert_int_eq(result.size(), parms.upper_bound - parms.lower_bound + 1);
     for (size_t i=0; i<result.size(); i++) {
@@ -194,21 +195,21 @@ START_TEST(t_range_query_merge)
     auto shard1 = Shard(buffer1);
     auto shard2 = Shard(buffer2);
 
-    pgm_range_query_parms<Rec> parms;
+    rq::Parms<Rec> parms;
     parms.lower_bound = 150;
     parms.upper_bound = 500;
 
     size_t result_size = parms.upper_bound - parms.lower_bound + 1 - 200;
 
-    auto state1 = PGMRangeQuery<Rec>::get_query_state(&shard1, &parms);
-    auto state2 = PGMRangeQuery<Rec>::get_query_state(&shard2, &parms);
+    auto state1 = rq::Query<Shard, Rec>::get_query_state(&shard1, &parms);
+    auto state2 = rq::Query<Shard, Rec>::get_query_state(&shard2, &parms);
 
     std::vector<std::vector<de::Wrapped<Rec>>> results(2);
-    results[0] = PGMRangeQuery<Rec>::query(&shard1, state1, &parms);
-    results[1] = PGMRangeQuery<Rec>::query(&shard2, state2, &parms);
+    results[0] = rq::Query<Shard, Rec>::query(&shard1, state1, &parms);
+    results[1] = rq::Query<Shard, Rec>::query(&shard2, state2, &parms);
 
-    PGMRangeQuery<Rec>::delete_query_state(state1);
-    PGMRangeQuery<Rec>::delete_query_state(state2);
+    rq::Query<Shard, Rec>::delete_query_state(state1);
+    rq::Query<Shard, Rec>::delete_query_state(state2);
 
     ck_assert_int_eq(results[0].size() + results[1].size(), result_size);
 
@@ -221,7 +222,7 @@ START_TEST(t_range_query_merge)
         }
     }
 
-    auto result = PGMRangeQuery<Rec>::merge(proc_results, nullptr);
+    auto result = rq::Query<Shard, Rec>::merge(proc_results, nullptr);
     std::sort(result.begin(), result.end());
 
     ck_assert_int_eq(result.size(), result_size);
diff --git a/tests/triespline_tests.cpp b/tests/triespline_tests.cpp
index 6f63961..101f143 100644
--- a/tests/triespline_tests.cpp
+++ b/tests/triespline_tests.cpp
@@ -13,6 +13,7 @@
 #include <functional>
 
 #include "shard/TrieSpline.h"
+#include "query/rangequery.h"
 #include "testing.h"
 
 #include <check.h>
@@ -176,13 +177,13 @@ START_TEST(t_range_query)
     auto buffer = create_sequential_mbuffer<Rec>(100, 1000);
     auto shard = Shard(buffer);
 
-    ts_range_query_parms<Rec> parms;
+    rq::Parms<Rec> parms;
     parms.lower_bound = 300;
     parms.upper_bound = 500;
 
-    auto state = TrieSplineRangeQuery<Rec>::get_query_state(&shard, &parms);
-    auto result = TrieSplineRangeQuery<Rec>::query(&shard, state, &parms);
-    TrieSplineRangeQuery<Rec>::delete_query_state(state);
+    auto state = rq::Query<Shard, Rec>::get_query_state(&shard, &parms);
+    auto result = rq::Query<Shard, Rec>::query(&shard, state, &parms);
+    rq::Query<Shard, Rec>::delete_query_state(state);
 
     ck_assert_int_eq(result.size(), parms.upper_bound - parms.lower_bound + 1);
     for (size_t i=0; i<result.size(); i++) {
@@ -199,13 +200,13 @@ START_TEST(t_buffer_range_query)
 {
     auto buffer = create_sequential_mbuffer<Rec>(100, 1000);
 
-    ts_range_query_parms<Rec> parms;
+    rq::Parms<Rec> parms;
     parms.lower_bound = 300;
     parms.upper_bound = 500;
 
-    auto state = TrieSplineRangeQuery<Rec>::get_buffer_query_state(buffer, &parms);
-    auto result = TrieSplineRangeQuery<Rec>::buffer_query(buffer, state, &parms);
-    TrieSplineRangeQuery<Rec>::delete_buffer_query_state(state);
+    auto state = rq::Query<Shard, Rec>::get_buffer_query_state(buffer, &parms);
+    auto result = rq::Query<Shard, Rec>::buffer_query(buffer, state, &parms);
+    rq::Query<Shard, Rec>::delete_buffer_query_state(state);
 
     ck_assert_int_eq(result.size(), parms.upper_bound - parms.lower_bound + 1);
     for (size_t i=0; i<result.size(); i++) {