1 files changed, 9 insertions, 2 deletions
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index e4fd1fd10b9..f0dd9621fbc 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -2895,12 +2895,19 @@ index_update_stats(Relation rel,
 	if (dirty)
 	{
 		systable_inplace_update_finish(state, tuple);
-		/* the above sends a cache inval message */
+		/* the above sends transactional and immediate cache inval messages */
 	}
 	else
 	{
 		systable_inplace_update_cancel(state);
-		/* no need to change tuple, but force relcache inval anyway */
+
+		/*
+		 * While we didn't change relhasindex, CREATE INDEX needs a
+		 * transactional inval for when the new index's catalog rows become
+		 * visible.  Other CREATE INDEX and REINDEX code happens to also queue
+		 * this inval, but keep this in case rare callers rely on this part of
+		 * our API contract.
+		 */
 		CacheInvalidateRelcacheByTuple(tuple);
 	}