From b7c2068b76b9380cf397baf8fe933121985b8646 Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Wed, 17 Jun 2026 11:27:24 -0700
Subject: [PATCH] Switched to TidStore for HNSW vacuuming for Postgres 17+

---
 src/hnsw.c       | 10 +++++++++-
 src/hnsw.h       |  8 +++++++-
 src/hnswvacuum.c | 32 +++++++++++++++++++++++++++++++-
 3 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/src/hnsw.c b/src/hnsw.c
index a3f5822..4b1017b 100644
--- a/src/hnsw.c
+++ b/src/hnsw.c
@@ -290,7 +290,11 @@ hnswhandler(PG_FUNCTION_ARGS)
 		.amcanparallel = false,
 		.amcanbuildparallel = true,
 		.amcaninclude = false,
+#if PG_VERSION_NUM >= 170000
+		.amusemaintenanceworkmem = true,
+#else
 		.amusemaintenanceworkmem = false,
+#endif
 		.amsummarizing = false,
 		.amparallelvacuumoptions = VACUUM_OPTION_PARALLEL_BULKDEL,
 		.amkeytype = InvalidOid,
@@ -351,7 +355,11 @@ hnswhandler(PG_FUNCTION_ARGS)
 	amroutine->amcanbuildparallel = true;
 #endif
 	amroutine->amcaninclude = false;
-	amroutine->amusemaintenanceworkmem = false; /* not used during VACUUM */
+#if PG_VERSION_NUM >= 170000
+	amroutine->amusemaintenanceworkmem = true;
+#else
+	amroutine->amusemaintenanceworkmem = false;
+#endif
 #if PG_VERSION_NUM >= 160000
 	amroutine->amsummarizing = false;
 #endif
diff --git a/src/hnsw.h b/src/hnsw.h
index 08293be..484db82 100644
--- a/src/hnsw.h
+++ b/src/hnsw.h
@@ -26,6 +26,12 @@
 typedef Pointer Item;
 #endif
 
+#if PG_VERSION_NUM >= 170000
+#define HnswTidStore TidStore
+#else
+#define HnswTidStore tidhash_hash
+#endif
+
 #define HNSW_MAX_DIM 2000
 #define HNSW_MAX_NNZ 1000
 
@@ -427,7 +433,7 @@ typedef struct HnswVacuumState
 	HnswSupport support;
 
 	/* Variables */
-	struct tidhash_hash *deleted;
+	struct HnswTidStore *deleted;
 	BufferAccessStrategy bas;
 	HnswNeighborTuple ntup;
 	HnswElementData highestPoint;
diff --git a/src/hnswvacuum.c b/src/hnswvacuum.c
index cdc3b94..91f37ab 100644
--- a/src/hnswvacuum.c
+++ b/src/hnswvacuum.c
@@ -10,6 +10,12 @@
 #include "utils/memutils.h"
 #include "utils/rel.h"
 
+#if PG_VERSION_NUM >= 170000
+#include "access/tidstore.h"
+#include "miscadmin.h"
+#include "postmaster/autovacuum.h"
+#endif
+
 #if PG_VERSION_NUM >= 160000
 #include "varatt.h"
 #endif
@@ -22,9 +28,13 @@
  * Check if deleted list contains an index TID
  */
 static bool
-DeletedContains(tidhash_hash * deleted, ItemPointer indextid)
+DeletedContains(HnswTidStore * deleted, ItemPointer indextid)
 {
+#if PG_VERSION_NUM >= 170000
+	return TidStoreIsMember(deleted, indextid);
+#else
 	return tidhash_lookup(deleted, *indextid) != NULL;
+#endif
 }
 
 /*
@@ -60,6 +70,10 @@ RemoveHeapTids(HnswVacuumState * vacuumstate)
 		OffsetNumber offno;
 		OffsetNumber maxoffno;
 		bool		updated = false;
+#if PG_VERSION_NUM >= 170000
+		OffsetNumber deletedoffs[MaxOffsetNumber];
+		int			ndeletedoffs = 0;
+#endif
 
 		vacuum_delay_point();
 
@@ -113,6 +127,9 @@ RemoveHeapTids(HnswVacuumState * vacuumstate)
 
 			if (!ItemPointerIsValid(&etup->heaptids[0]))
 			{
+#if PG_VERSION_NUM >= 170000
+				deletedoffs[ndeletedoffs++] = offno;
+#else
 				ItemPointerData ip;
 				bool		found;
 
@@ -121,6 +138,7 @@ RemoveHeapTids(HnswVacuumState * vacuumstate)
 
 				tidhash_insert(vacuumstate->deleted, ip, &found);
 				Assert(!found);
+#endif
 			}
 			else if (etup->level > highestLevel)
 			{
@@ -149,6 +167,10 @@ RemoveHeapTids(HnswVacuumState * vacuumstate)
 			}
 		}
 
+#if PG_VERSION_NUM >= 170000
+		TidStoreSetBlockOffsets(vacuumstate->deleted, blkno, deletedoffs, ndeletedoffs);
+#endif
+
 		blkno = HnswPageGetOpaque(page)->nextblkno;
 
 		if (updated)
@@ -739,7 +761,11 @@ InitVacuumState(HnswVacuumState * vacuumstate, IndexVacuumInfo *info, IndexBulkD
 	HnswGetMetaPageInfo(index, &vacuumstate->m, NULL);
 
 	/* Create hash table */
+#if PG_VERSION_NUM >= 170000
+	vacuumstate->deleted = TidStoreCreateLocal((AmAutoVacuumWorkerProcess() && autovacuum_work_mem != -1) ? autovacuum_work_mem : maintenance_work_mem, true);
+#else
 	vacuumstate->deleted = tidhash_create(CurrentMemoryContext, 256, NULL);
+#endif
 }
 
 /*
@@ -748,7 +774,11 @@ InitVacuumState(HnswVacuumState * vacuumstate, IndexVacuumInfo *info, IndexBulkD
 static void
 FreeVacuumState(HnswVacuumState * vacuumstate)
 {
+#if PG_VERSION_NUM >= 170000
+	TidStoreDestroy(vacuumstate->deleted);
+#else
 	tidhash_destroy(vacuumstate->deleted);
+#endif
 	FreeAccessStrategy(vacuumstate->bas);
 	pfree(vacuumstate->ntup);
 	MemoryContextDelete(vacuumstate->tmpCtx);