Added benchmarking for HNSW vacuuming [skip ci]

.github/workflows/build.yml

@@ -97,7 +97,7 @@ jobs:
         with:
           postgres-version: ${{ matrix.postgres }}
       - run: |
-          call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvars64.bat" && ^
+          call "C:\Program Files\Microsoft Visual Studio\${{ matrix.os == 'windows-2025' && 18 || 2022 }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat" && ^
           nmake /NOLOGO /F Makefile.win && ^
           nmake /NOLOGO /F Makefile.win install && ^
           nmake /NOLOGO /F Makefile.win installcheck ${{ matrix.postgres != 17 && 'PG_REGRESS=$(PGROOT)\bin\pg_regress' || '' }} && ^

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.8.3 (unreleased)
+
+- Fixed performance regression with Hamming distance and Jaccard distance with Postgres 18
+
 ## 0.8.2 (2026-02-25)
 
 - Fixed buffer overflow with parallel HNSW index build - [more info](https://github.com/pgvector/pgvector/issues/959)

README.md

@@ -1329,7 +1329,7 @@ make clean && PG_CFLAGS="-DUSE_ASSERT_CHECKING" make && make install
 To enable benchmarking:
 
 ```sh
-make clean && PG_CFLAGS="-DIVFFLAT_BENCH" make && make install
+make clean && PG_CFLAGS="-DHNSW_BENCH -DIVFFLAT_BENCH" make && make install
 ```
 
 To show memory usage:

src/bitutils.c

@@ -31,10 +31,12 @@
 #define BIT_TARGET_CLONES
 #endif
 
-/* Use built-ins when possible for inlining */
-#if defined(HAVE__BUILTIN_POPCOUNT) && defined(HAVE_LONG_INT_64)
+/* Use built-ins when possible for Postgres < 19 for inlining */
+#if PG_VERSION_NUM >= 190000
+#define popcount64(x) pg_popcount64(x)
+#elif defined(HAVE__BUILTIN_POPCOUNT) && (defined(HAVE_LONG_INT_64) || SIZEOF_LONG == 8)
 #define popcount64(x) __builtin_popcountl(x)
-#elif defined(HAVE__BUILTIN_POPCOUNT) && defined(HAVE_LONG_LONG_INT_64)
+#elif defined(HAVE__BUILTIN_POPCOUNT) && (defined(HAVE_LONG_LONG_INT_64) || SIZEOF_LONG_LONG == 8)
 #define popcount64(x) __builtin_popcountll(x)
 #elif !defined(_MSC_VER)
 /* Fails to resolve with MSVC */

src/hnsw.c

@@ -258,11 +258,6 @@ hnswvalidate(Oid opclassoid)
 	return true;
 }
 
-static void
-hnswunguardbatch(IndexScanDesc scan, IndexScanBatch batch)
-{
-}
-
 /*
  * Define index handler
  *
@@ -284,7 +279,6 @@ hnswhandler(PG_FUNCTION_ARGS)
 		.amconsistentequality = false,
 		.amconsistentordering = false,
 		.amcanbackward = false,
-		.amcanmarkpos = false,
 		.amcanunique = false,
 		.amcanmulticol = false,
 		.amoptionalkey = true,
@@ -317,14 +311,11 @@ hnswhandler(PG_FUNCTION_ARGS)
 		.amadjustmembers = NULL,
 		.ambeginscan = hnswbeginscan,
 		.amrescan = hnswrescan,
-		.amgettuple = NULL,
-		.amgetbatch = hnswgetbatch,
-		.amunguardbatch = hnswunguardbatch,
-		.amkillitemsbatch = NULL,
-		.amgettransform = NULL,
+		.amgettuple = hnswgettuple,
 		.amgetbitmap = NULL,
 		.amendscan = hnswendscan,
-		.amposreset = NULL,
+		.ammarkpos = NULL,
+		.amrestrpos = NULL,
 		.amestimateparallelscan = NULL,
 		.aminitparallelscan = NULL,
 		.amparallelrescan = NULL,

src/hnsw.h

@@ -18,6 +18,10 @@
 #include "utils/sampling.h"
 #include "vector.h"
 
+#ifdef HNSW_BENCH
+#include "portability/instr_time.h"
+#endif
+
 #if PG_VERSION_NUM >= 190000
 typedef Pointer Item;
 #endif
@@ -78,6 +82,21 @@ typedef Pointer Item;
 #define HnswPageGetOpaque(page)	((HnswPageOpaque) PageGetSpecialPointer(page))
 #define HnswPageGetMeta(page)	((HnswMetaPageData *) PageGetContents(page))
 
+#ifdef HNSW_BENCH
+#define HnswBench(name, code) \
+	do { \
+		instr_time	start; \
+		instr_time	duration; \
+		INSTR_TIME_SET_CURRENT(start); \
+		(code); \
+		INSTR_TIME_SET_CURRENT(duration); \
+		INSTR_TIME_SUBTRACT(duration, start); \
+		elog(INFO, "%s: %.3f ms", name, INSTR_TIME_GET_MILLISEC(duration)); \
+	} while (0)
+#else
+#define HnswBench(name, code) (code)
+#endif
+
 #if PG_VERSION_NUM >= 150000
 #define RandomDouble() pg_prng_double(&pg_global_prng_state)
 #define SeedRandom(seed) pg_prng_seed(&pg_global_prng_state, seed)
@@ -465,7 +484,7 @@ IndexBulkDeleteResult *hnswbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResu
 IndexBulkDeleteResult *hnswvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats);
 IndexScanDesc hnswbeginscan(Relation index, int nkeys, int norderbys);
 void		hnswrescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys);
-IndexScanBatch hnswgetbatch(IndexScanDesc scan, IndexScanBatch priorbatch, ScanDirection dir);
+bool		hnswgettuple(IndexScanDesc scan, ScanDirection dir);
 void		hnswendscan(IndexScanDesc scan);
 
 static inline HnswNeighborArray *

src/hnswscan.c

@@ -3,7 +3,6 @@
 #include <limits.h>
 
 #include "access/genam.h"
-#include "access/indexbatch.h"
 #include "access/relscan.h"
 #include "hnsw.h"
 #include "lib/pairingheap.h"
@@ -136,11 +135,6 @@ hnswbeginscan(Relation index, int nkeys, int norderbys)
 	double		maxMemory;
 
 	scan = RelationGetIndexScan(index, nkeys, norderbys);
-	scan->maxitemsbatch = hnsw_ef_search * HNSW_HEAPTIDS;
-	/* unused but must be > 0 */
-	scan->batch_index_opaque_static = MAXALIGN(1);
-	scan->batch_index_opaque_dyn = 0;
-	scan->batch_tuples_workspace = 0;
 
 	so = (HnswScanOpaque) palloc(sizeof(HnswScanOpaqueData));
 	so->typeInfo = HnswGetTypeInfo(index);
@@ -190,13 +184,12 @@ hnswrescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int no
 }
 
 /*
- * Fetch the next batch in the given scan
+ * Fetch the next tuple in the given scan
  */
-IndexScanBatch
-hnswgetbatch(IndexScanDesc scan, IndexScanBatch priorbatch, ScanDirection dir)
+bool
+hnswgettuple(IndexScanDesc scan, ScanDirection dir)
 {
 	HnswScanOpaque so = (HnswScanOpaque) scan->opaque;
-	IndexScanBatch batch = indexam_util_alloc_batch(scan);
 	MemoryContext oldCtx = MemoryContextSwitchTo(so->tmpCtx);
 
 	/*
@@ -252,7 +245,6 @@ hnswgetbatch(IndexScanDesc scan, IndexScanBatch priorbatch, ScanDirection dir)
 		HnswSearchCandidate *sc;
 		HnswElement element;
 		ItemPointer heaptid;
-		int			nitems = 0;
 
 		if (list_length(so->w) == 0)
 		{
@@ -298,64 +290,44 @@ hnswgetbatch(IndexScanDesc scan, IndexScanBatch priorbatch, ScanDirection dir)
 				break;
 		}
 
-		while (list_length(so->w) != 0)
+		sc = llast(so->w);
+		element = HnswPtrAccess(base, sc->element);
+
+		/* Move to next element if no valid heap TIDs */
+		if (element->heaptidsLength == 0)
 		{
-			sc = llast(so->w);
-			element = HnswPtrAccess(base, sc->element);
+			so->w = list_delete_last(so->w);
 
-			/* Move to next element if no valid heap TIDs */
-			if (element->heaptidsLength == 0)
+			/* Mark memory as free for next iteration */
+			if (hnsw_iterative_scan != HNSW_ITERATIVE_SCAN_OFF)
 			{
-				so->w = list_delete_last(so->w);
-
-				/* Mark memory as free for next iteration */
-				if (hnsw_iterative_scan != HNSW_ITERATIVE_SCAN_OFF)
-				{
-					pfree(element);
-					pfree(sc);
-				}
-
-				continue;
+				pfree(element);
+				pfree(sc);
 			}
 
-			heaptid = &element->heaptids[--element->heaptidsLength];
-
-			if (hnsw_iterative_scan == HNSW_ITERATIVE_SCAN_STRICT)
-			{
-				if (sc->distance < so->previousDistance)
-					continue;
-
-				so->previousDistance = sc->distance;
-			}
-
-			batch->items[nitems].tableTid = *heaptid;
-			batch->items[nitems].indexOffset = -1;
-			batch->items[nitems].tupleOffset = 0;
-			nitems++;
-
-			/* Keep batch size flexible */
-			if (nitems == scan->maxitemsbatch)
-				break;
+			continue;
 		}
 
-		/* Needed for strict iterative scans */
-		if (nitems == 0)
-			continue;
+		heaptid = &element->heaptids[--element->heaptidsLength];
+
+		if (hnsw_iterative_scan == HNSW_ITERATIVE_SCAN_STRICT)
+		{
+			if (sc->distance < so->previousDistance)
+				continue;
+
+			so->previousDistance = sc->distance;
+		}
 
 		MemoryContextSwitchTo(oldCtx);
 
+		scan->xs_heaptid = *heaptid;
 		scan->xs_recheck = false;
 		scan->xs_recheckorderby = false;
-
-		batch->firstItem = 0;
-		batch->lastItem = nitems - 1;
-		batch->dir = ForwardScanDirection;
-		return batch;
+		return true;
 	}
 
 	MemoryContextSwitchTo(oldCtx);
-	indexam_util_release_batch(scan, batch);
-	return NULL;
+	return false;
 }
 
 /*

src/hnswvacuum.c

@@ -634,13 +634,13 @@ hnswbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 	InitVacuumState(&vacuumstate, info, stats, callback, callback_state);
 
 	/* Pass 1: Remove heap TIDs */
-	RemoveHeapTids(&vacuumstate);
+	HnswBench("RemoveHeapTids", RemoveHeapTids(&vacuumstate));
 
 	/* Pass 2: Repair graph */
-	RepairGraph(&vacuumstate);
+	HnswBench("RepairGraph", RepairGraph(&vacuumstate));
 
 	/* Pass 3: Mark as deleted */
-	MarkDeleted(&vacuumstate);
+	HnswBench("MarkDeleted", MarkDeleted(&vacuumstate));
 
 	FreeVacuumState(&vacuumstate);
 

src/ivfflat.c

@@ -175,11 +175,6 @@ ivfflatvalidate(Oid opclassoid)
 	return true;
 }
 
-static void
-ivfflatunguardbatch(IndexScanDesc scan, IndexScanBatch batch)
-{
-}
-
 /*
  * Define index handler
  *
@@ -201,7 +196,6 @@ ivfflathandler(PG_FUNCTION_ARGS)
 		.amconsistentequality = false,
 		.amconsistentordering = false,
 		.amcanbackward = false,
-		.amcanmarkpos = false,
 		.amcanunique = false,
 		.amcanmulticol = false,
 		.amoptionalkey = true,
@@ -234,14 +228,11 @@ ivfflathandler(PG_FUNCTION_ARGS)
 		.amadjustmembers = NULL,
 		.ambeginscan = ivfflatbeginscan,
 		.amrescan = ivfflatrescan,
-		.amgettuple = NULL,
-		.amgetbatch = ivfflatgetbatch,
-		.amunguardbatch = ivfflatunguardbatch,
-		.amkillitemsbatch = NULL,
-		.amgettransform = NULL,
+		.amgettuple = ivfflatgettuple,
 		.amgetbitmap = NULL,
 		.amendscan = ivfflatendscan,
-		.amposreset = NULL,
+		.ammarkpos = NULL,
+		.amrestrpos = NULL,
 		.amestimateparallelscan = NULL,
 		.aminitparallelscan = NULL,
 		.amparallelrescan = NULL,

src/ivfflat.h

@@ -344,7 +344,7 @@ IndexBulkDeleteResult *ivfflatbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteR
 IndexBulkDeleteResult *ivfflatvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats);
 IndexScanDesc ivfflatbeginscan(Relation index, int nkeys, int norderbys);
 void		ivfflatrescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys);
-IndexScanBatch ivfflatgetbatch(IndexScanDesc scan, IndexScanBatch priorbatch, ScanDirection dir);
+bool		ivfflatgettuple(IndexScanDesc scan, ScanDirection dir);
 void		ivfflatendscan(IndexScanDesc scan);
 
 #endif

src/ivfscan.c

@@ -3,7 +3,6 @@
 #include <float.h>
 
 #include "access/genam.h"
-#include "access/indexbatch.h"
 #include "access/itup.h"
 #include "access/relscan.h"
 #include "access/tupdesc.h"
@@ -262,11 +261,6 @@ ivfflatbeginscan(Relation index, int nkeys, int norderbys)
 	MemoryContext oldCtx;
 
 	scan = RelationGetIndexScan(index, nkeys, norderbys);
-	scan->maxitemsbatch = 1000;
-	/* unused but must be > 0 */
-	scan->batch_index_opaque_static = MAXALIGN(1);
-	scan->batch_index_opaque_dyn = 0;
-	scan->batch_tuples_workspace = 0;
 
 	/* Get lists and dimensions from metapage */
 	IvfflatGetMetaPageInfo(index, &lists, &dimensions);
@@ -354,16 +348,14 @@ ivfflatrescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int
 }
 
 /*
- * Fetch the next batch in the given scan
+ * Fetch the next tuple in the given scan
  */
-IndexScanBatch
-ivfflatgetbatch(IndexScanDesc scan, IndexScanBatch priorbatch, ScanDirection dir)
+bool
+ivfflatgettuple(IndexScanDesc scan, ScanDirection dir)
 {
 	IvfflatScanOpaque so = (IvfflatScanOpaque) scan->opaque;
-	IndexScanBatch batch = indexam_util_alloc_batch(scan);
 	ItemPointer heaptid;
 	bool		isnull;
-	int			nitems = 0;
 
 	/*
 	 * Index can be used to scan backward, but Postgres doesn't support
@@ -401,37 +393,17 @@ ivfflatgetbatch(IndexScanDesc scan, IndexScanBatch priorbatch, ScanDirection dir
 	while (!tuplesort_gettupleslot(so->sortstate, true, false, so->mslot, NULL))
 	{
 		if (so->listIndex == so->maxProbes)
-		{
-			indexam_util_release_batch(scan, batch);
-			return NULL;
-		}
+			return false;
 
 		IvfflatBench("GetScanItems", GetScanItems(scan, so->value));
 	}
 
-	for (;;)
-	{
-		heaptid = (ItemPointer) DatumGetPointer(slot_getattr(so->mslot, 2, &isnull));
-
-		batch->items[nitems].tableTid = *heaptid;
-		batch->items[nitems].indexOffset = -1;
-		batch->items[nitems].tupleOffset = 0;
-		nitems++;
-
-		if (nitems == scan->maxitemsbatch)
-			break;
-
-		if (!tuplesort_gettupleslot(so->sortstate, true, false, so->mslot, NULL))
-			break;
-	}
+	heaptid = (ItemPointer) DatumGetPointer(slot_getattr(so->mslot, 2, &isnull));
 
+	scan->xs_heaptid = *heaptid;
 	scan->xs_recheck = false;
 	scan->xs_recheckorderby = false;
-
-	batch->firstItem = 0;
-	batch->lastItem = nitems - 1;
-	batch->dir = ForwardScanDirection;
-	return batch;
+	return true;
 }
 
 /*