Remove overzealous index deletion assertion.

petergeoghegan · petergeoghegan · commit a1708ab652ea · 2021-09-20T14:26:22.000-07:00
A broken HOT chain is not an unexpected condition, even when the offset number points past the end of the page's line pointer array. heap_prune_chain() does not (and never has) treated this condition as unexpected, so derivative code in heap_index_delete_tuples() shouldn't do so either. Oversight in commit 4228817. The assertion can probably only fail on Postgres 14 and master. Earlier releases don't have commit 3c3b8a4, which taught VACUUM to truncate the line pointer array of heap pages. Backpatch all the same, just to be consistent. Author: Peter Geoghegan <pg@bowt.ie> Reported-By: Alexander Lakhin <exclusion@gmail.com> Discussion: https://postgr.es/m/17197-9438f31f46705182@postgresql.org Backpatch: 12-, just like commit 4228817.
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
@@ -7093,10 +7093,7 @@ heap_compute_xid_horizon_for_tuples(Relation rel,
 
 			/* Some sanity checks */
 			if (offnum < FirstOffsetNumber || offnum > maxoff)
-			{
-				Assert(false);
 				break;
-			}
 
 			lp = PageGetItemId(page, offnum);
 			if (ItemIdIsRedirected(lp))
