During index build, check and elog (not just Assert) for broken HOT chain.

The recently-fixed bug in WAL replay could result in not finding a parent
tuple for a heap-only tuple.  The existing code would either Assert or
generate an invalid index entry, neither of which is desirable.  Throw a
regular error instead.

diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 877d7678f7ae1f5a31c23f35ba095024b6d0f447..432067488b77285f4d019b287153930694d513d3 100644 (file)
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -2438,7 +2438,10 @@ IndexBuildHeapScan(Relation heapRelation,
                        rootTuple = *heapTuple;
                        offnum = ItemPointerGetOffsetNumber(&heapTuple->t_self);
 
-                       Assert(OffsetNumberIsValid(root_offsets[offnum - 1]));
+                       if (!OffsetNumberIsValid(root_offsets[offnum - 1]))
+                               elog(ERROR, "failed to find parent tuple for heap-only tuple at (%u,%u) in table \"%s\"",
+                                        ItemPointerGetBlockNumber(&heapTuple->t_self),
+                                        offnum, RelationGetRelationName(heapRelation));
 
                        ItemPointerSetOffsetNumber(&rootTuple.t_self,
                                                                           root_offsets[offnum - 1]);
@@ -2856,7 +2859,11 @@ validate_index_heapscan(Relation heapRelation,
                if (HeapTupleIsHeapOnly(heapTuple))
                {
                        root_offnum = root_offsets[root_offnum - 1];
-                       Assert(OffsetNumberIsValid(root_offnum));
+                       if (!OffsetNumberIsValid(root_offnum))
+                               elog(ERROR, "failed to find parent tuple for heap-only tuple at (%u,%u) in table \"%s\"",
+                                        ItemPointerGetBlockNumber(heapcursor),
+                                        ItemPointerGetOffsetNumber(heapcursor),
+                                        RelationGetRelationName(heapRelation));
                        ItemPointerSetOffsetNumber(&rootTuple, root_offnum);
                }