From 3aa4cb9ea6e2e84d1f075f0fdd6d0db8765feb9b Mon Sep 17 00:00:00 2001 From: xiaoyu liu Date: Mon, 7 Sep 2026 16:49:19 +0800 Subject: [PATCH] tableam: Assume successful scans return nonempty slots Record the one-way scan_getnextslot contract with pg_assume so the compiler can remove a redundant slot emptiness check from executor scan paths. --- src/include/access/tableam.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h index ff03a2b816f..b4cac9b177c 100644 --- a/src/include/access/tableam.h +++ b/src/include/access/tableam.h @@ -378,7 +378,8 @@ typedef struct TableAmRoutine bool allow_sync, bool allow_pagemode); /* - * Return next tuple from `scan`, store in slot. + * Return true if the next tuple from `scan` was stored in slot. A + * successful call must leave slot non-empty. */ bool (*scan_getnextslot) (TableScanDesc scan, ScanDirection direction, @@ -1095,13 +1096,18 @@ table_rescan_set_params(TableScanDesc scan, ScanKeyData *key, static inline bool table_scan_getnextslot(TableScanDesc sscan, ScanDirection direction, TupleTableSlot *slot) { + bool found; + slot->tts_tableOid = RelationGetRelid(sscan->rs_rd); /* We don't expect actual scans using NoMovementScanDirection */ Assert(direction == ForwardScanDirection || direction == BackwardScanDirection); - return sscan->rs_rd->rd_tableam->scan_getnextslot(sscan, direction, slot); + found = sscan->rs_rd->rd_tableam->scan_getnextslot(sscan, direction, slot); + pg_assume(!found || !TupIsNull(slot)); + + return found; } /* ---------------------------------------------------------------------------- -- 2.44.0