Internal duckdb#330: Quantile Performance Review

Incorporate Carlo's review (thanks!)
hawkfish · Oct 30, 2023 · 67f0fd4 · 67f0fd4
1 parent 300e8c0
commit 67f0fd4
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Showing 3 changed files with 10 additions and 4 deletions.
diff --git a/src/core_functions/aggregate/holistic/quantile.cpp b/src/core_functions/aggregate/holistic/quantile.cpp
@@ -733,9 +733,13 @@ struct QuantileState {
 			return qst64->WindowScalar<INPUT_TYPE, RESULT_TYPE, DISCRETE>(data, frames, n, result, q);
 		} else if (s) {
 			// Find the position(s) needed
-			Interpolator<DISCRETE> interp(q, s->size(), false);
-			s->at(interp.FRN, interp.CRN - interp.FRN + 1, dest);
-			return interp.template Extract<INPUT_TYPE, RESULT_TYPE>(dest.data(), result);
+			try {
+				Interpolator<DISCRETE> interp(q, s->size(), false);
+				s->at(interp.FRN, interp.CRN - interp.FRN + 1, dest);
+				return interp.template Extract<INPUT_TYPE, RESULT_TYPE>(dest.data(), result);
+			} catch (const duckdb_skiplistlib::skip_list::IndexError &idx_err) {
+				throw InternalException(idx_err.message());
+			}
 		} else {
 			throw InternalException("No accelerator for scalar QUANTILE");
 		}

diff --git a/third_party/skiplist/Node.h b/third_party/skiplist/Node.h
@@ -38,6 +38,7 @@
 #define SkipList_Node_h
 
 #include "IntegrityEnums.h"
+#include <random>
 
 #if __cplusplus < 201103L
 #define nullptr NULL
@@ -129,7 +130,7 @@ class Node {
     Node<T, _Compare> *_adjRemoveRefs(size_t level, Node<T, _Compare> *pNode);
 
 	void Initialize(const T &value) {
-		_value = value;
+		::std::independent_bits_engine<::std::default_random_engine, /*bits*/ 1, int> tossCoin;
 		_nodeRefs.clear();
 		do {
 			_nodeRefs.push_back(this, _nodeRefs.height() ? 0 : 1);

diff --git a/third_party/skiplist/SkipList.h b/third_party/skiplist/SkipList.h
@@ -446,6 +446,7 @@
 #include <vector>
 #include <set> // Used for HeadNode::_lacksIntegrityNodeReferencesNotInList()
 #include <string> // Used for class Exception
+#include <random>
 
 #ifdef DEBUG
 #include <cassert>