From e4c2373031b2c0313547577b019b1d30cd03b83d Mon Sep 17 00:00:00 2001 From: Peter Geoghegan Date: Wed, 17 Nov 2021 17:58:48 -0800 Subject: [PATCH v1] Don't avoid applying HOT when page is marked full. --- src/backend/access/heap/heapam.c | 31 ++++++------------------------- 1 file changed, 6 insertions(+), 25 deletions(-) diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index ec234a5e5..29a4bf0c7 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -3179,7 +3179,6 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup, bool have_tuple_lock = false; bool iscombo; bool use_hot_update = false; - bool hot_attrs_checked = false; bool key_intact; bool all_visible_cleared = false; bool all_visible_cleared_new = false; @@ -3228,32 +3227,15 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup, key_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_KEY); id_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_IDENTITY_KEY); - + interesting_attrs = NULL; + interesting_attrs = bms_add_members(interesting_attrs, hot_attrs); + interesting_attrs = bms_add_members(interesting_attrs, key_attrs); + interesting_attrs = bms_add_members(interesting_attrs, id_attrs); block = ItemPointerGetBlockNumber(otid); buffer = ReadBuffer(relation, block); page = BufferGetPage(buffer); - interesting_attrs = NULL; - - /* - * If the page is already full, there is hardly any chance of doing a HOT - * update on this page. It might be wasteful effort to look for index - * column updates only to later reject HOT updates for lack of space in - * the same page. So we be conservative and only fetch hot_attrs if the - * page is not already full. Since we are already holding a pin on the - * buffer, there is no chance that the buffer can get cleaned up - * concurrently and even if that was possible, in the worst case we lose a - * chance to do a HOT update. - */ - if (!PageIsFull(page)) - { - interesting_attrs = bms_add_members(interesting_attrs, hot_attrs); - hot_attrs_checked = true; - } - interesting_attrs = bms_add_members(interesting_attrs, key_attrs); - interesting_attrs = bms_add_members(interesting_attrs, id_attrs); - /* * Before locking the buffer, pin the visibility map page if it appears to * be necessary. Since we haven't got the lock yet, someone else might be @@ -3867,10 +3849,9 @@ l2: /* * Since the new tuple is going into the same page, we might be able * to do a HOT update. Check if any of the index columns have been - * changed. If the page was already full, we may have skipped checking - * for index columns, and also can't do a HOT update. + * changed. */ - if (hot_attrs_checked && !bms_overlap(modified_attrs, hot_attrs)) + if (!bms_overlap(modified_attrs, hot_attrs)) use_hot_update = true; } else -- 2.30.2