Use ItemPointer comparison in comparetup_rum() only in full-scan

Artur Zakirov · Artur Zakirov · commit 582707895892 · 2016-06-02T19:27:22.000+03:00
diff --git a/rumget.c b/rumget.c
@@ -2534,7 +2534,10 @@ rumgettuple(IndexScanDesc scan, ScanDirection direction)
 		so->tbm = NULL;
 		so->entriesIncrIndex = -1;
 		so->firstCall = false;
-		so->sortstate = rum_tuplesort_begin_rum(work_mem, so->norderbys, false);
+		so->sortstate = rum_tuplesort_begin_rum(work_mem, so->norderbys, false,
+												so->totalentries > 0 &&
+												so->entries[0]->queryCategory == RUM_CAT_EMPTY_QUERY &&
+												so->entries[0]->scanWithAddInfo);
 
 		scanPendingInsert(scan);
 
diff --git a/rumsort.c b/rumsort.c
@@ -405,6 +405,9 @@ struct Tuplesortstate
 
 	bool		reverse;
 
+	/* Do we need ItemPointer comparison in comparetup_rum()? */
+	bool		compareItemPointer;
+
 	/*
 	 * Resource snapshot for time of sort start.
 	 */
@@ -1124,7 +1127,8 @@ rum_tuplesort_begin_index_hash(Relation heapRel,
 }
 
 Tuplesortstate *
-rum_tuplesort_begin_rum(int workMem, int nKeys, bool randomAccess)
+rum_tuplesort_begin_rum(int workMem, int nKeys, bool randomAccess,
+						bool compareItemPointer)
 {
 	Tuplesortstate *state = rum_tuplesort_begin_common(workMem, randomAccess);
 	MemoryContext oldcontext;
@@ -1152,6 +1156,7 @@ rum_tuplesort_begin_rum(int workMem, int nKeys, bool randomAccess)
 	state->readtup = readtup_rum;
 	state->reversedirection = reversedirection_rum;
 	state->reverse = false;
+	state->compareItemPointer = compareItemPointer;
 
 	MemoryContextSwitchTo(oldcontext);
 
@@ -3865,6 +3870,9 @@ comparetup_rum(const SortTuple *a, const SortTuple *b, Tuplesortstate *state)
 			return 1;
 	}
 
+	if (!state->compareItemPointer)
+		return 0;
+
 	/*
 	 * If key values are equal, we sort on ItemPointer.
 	 */
diff --git a/rumsort.h b/rumsort.h
@@ -89,7 +89,7 @@ extern Tuplesortstate *rum_tuplesort_begin_datum(Oid datumType,
 						  bool nullsFirstFlag,
 						  int workMem, bool randomAccess);
 extern Tuplesortstate *rum_tuplesort_begin_rum(int workMem,
-						int nKeys, bool randomAccess);
+						int nKeys, bool randomAccess, bool compareItemPointer);
 
 extern void rum_tuplesort_set_bound(Tuplesortstate *state, int64 bound);
 
