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authorDouglas Rumbaugh <dbr4@psu.edu>2025-05-04 16:43:45 -0400
committerDouglas Rumbaugh <dbr4@psu.edu>2025-05-04 16:43:45 -0400
commiteb519d35d7f11427dd5fc877130b02478f0da80d (patch)
tree2eb5bc349c82517fdc6484fce71c862b92b0213b /chapters/background.tex
parent873fd659e45e80fe9e229d3d85b3c4c99fb2c121 (diff)
downloaddissertation-eb519d35d7f11427dd5fc877130b02478f0da80d.tar.gz
Began re-writing/updating the sampling extension stuff
Diffstat (limited to 'chapters/background.tex')
-rw-r--r--chapters/background.tex13
1 files changed, 4 insertions, 9 deletions
diff --git a/chapters/background.tex b/chapters/background.tex
index 9950b39..69436c8 100644
--- a/chapters/background.tex
+++ b/chapters/background.tex
@@ -85,6 +85,7 @@ their work on dynamization, and we will adopt their definition,
\begin{equation*}
F(A \cup B, q) = F(A, q)~ \mergeop ~F(B, q)
\end{equation*}
+ for all $A, B \in \mathcal{PS}(\mathcal{D})$ where $A \cap B = \emptyset$.
\end{definition}
The requirement for $\mergeop$ to be constant-time was used by Bentley and
@@ -101,6 +102,7 @@ problems},
\begin{equation*}
F(A \cup B, q) = F(A, q)~ \mergeop ~F(B, q)
\end{equation*}
+ for all $A, B \in \mathcal{PS}(\mathcal{D})$ where $A \cap B = \emptyset$.
\end{definition}
To demonstrate that a search problem is decomposable, it is necessary to
@@ -811,6 +813,7 @@ cost, we could greatly reduce the cost of supporting $C(n)$-decomposable
queries.
\subsubsection{Independent Range Sampling}
+\label{ssec:background-irs}
Another problem that is not decomposable is independent sampling. There
are a variety of problems falling under this umbrella, including weighted
@@ -831,15 +834,7 @@ matching of records in result sets. To work around this, a slight abuse
of definition is in order: assume that the equality conditions within
the DSP definition can be interpreted to mean ``the contents in the two
sets are drawn from the same distribution''. This enables the category
-of DSP to apply to this type of problem. More formally,
-\begin{definition}[Decomposable Sampling Problem]
- A sampling problem $F: (D, Q) \to R$, $F$ is decomposable if and
- only if there exists a constant-time computable, associative, and
- commutative binary operator $\mergeop$ such that,
- \begin{equation*}
- F(A \cup B, q) \sim F(A, q)~ \mergeop ~F(B, q)
- \end{equation*}
-\end{definition}
+of DSP to apply to this type of problem.
Even with this abuse, however, IRS cannot generally be considered
decomposable; it is at best $C(n)$-decomposable. The reason for this is