Under wal_level=logical, when saving old tuples, always save OID.

There's no real point in not doing this.  It doesn't cost anything
in performance or space.  So let's go wild.

Andres Freund, with substantial editing as to style by me.

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 249fffeb0615ae5d07598d9693f25ef2ad4ce00e..09174b472b06a00b6aa74db9b7f1690e7a34eafb 100644 (file)
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -6638,7 +6638,6 @@ ExtractReplicaIdentity(Relation relation, HeapTuple tp, bool key_changed, bool *
    TupleDesc   idx_desc;
    char        replident = relation->rd_rel->relreplident;
    HeapTuple   key_tuple = NULL;
-   bool        copy_oid = false;
    bool        nulls[MaxHeapAttributeNumber];
    Datum       values[MaxHeapAttributeNumber];
    int         natt;
@@ -6697,20 +6696,30 @@ ExtractReplicaIdentity(Relation relation, HeapTuple tp, bool key_changed, bool *
    {
        int attno = idx_rel->rd_index->indkey.values[natt];
 
-       if (attno == ObjectIdAttributeNumber)
-           copy_oid = true;
-       else if (attno < 0)
+       if (attno < 0)
+       {
+           /*
+            * The OID column can appear in an index definition, but that's
+            * OK, becuse we always copy the OID if present (see below).
+            * Other system columns may not.
+            */
+           if (attno == ObjectIdAttributeNumber)
+               continue;
            elog(ERROR, "system column in index");
-       else
-           nulls[attno - 1] = false;
+       }
+       nulls[attno - 1] = false;
    }
 
    key_tuple = heap_form_tuple(desc, values, nulls);
    *copy = true;
    RelationClose(idx_rel);
 
-   /* XXX: we could also do this unconditionally, the space is used anyway */
-   if (copy_oid)
+   /*
+    * Always copy oids if the table has them, even if not included in the
+    * index. The space in the logged tuple is used anyway, so there's little
+    * point in not including the information.
+    */
+   if (relation->rd_rel->relhasoids)
        HeapTupleSetOid(key_tuple, HeapTupleGetOid(tp));
 
    /*