From: Peter Geoghegan <pg@bowt.ie>
Date: Mon, 9 Sep 2019 18:41:19 +0000 (-0700)
Subject: Add _bt_binsrch() scantid assertion to nbtree.
X-Git-Tag: aio-before-rebase-2020-06-24~1757
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=55d015bde05311cbaaf16424e3aa05c37946cd8a;p=users%2Fandresfreund%2Fpostgres.git

Add _bt_binsrch() scantid assertion to nbtree.

Assert that _bt_binsrch() binary searches with scantid set in insertion
scankey cannot be performed on leaf pages.  Leaf-level binary searches
where scantid is set must use _bt_binsrch_insert() instead.

_bt_binsrch_insert() is likely to have additional responsibilities in
the future, such as searching within GIN-style posting lists using
scantid.  It seems like a good idea to tighten things up now.
---

diff --git a/src/backend/access/nbtree/nbtsearch.c b/src/backend/access/nbtree/nbtsearch.c
index 7f77ed24c5..8e512461a0 100644
--- a/src/backend/access/nbtree/nbtsearch.c
+++ b/src/backend/access/nbtree/nbtsearch.c
@@ -347,12 +347,14 @@ _bt_binsrch(Relation rel,
 	int32		result,
 				cmpval;
 
-	/* Requesting nextkey semantics while using scantid seems nonsensical */
-	Assert(!key->nextkey || key->scantid == NULL);
-
 	page = BufferGetPage(buf);
 	opaque = (BTPageOpaque) PageGetSpecialPointer(page);
 
+	/* Requesting nextkey semantics while using scantid seems nonsensical */
+	Assert(!key->nextkey || key->scantid == NULL);
+	/* scantid-set callers must use _bt_binsrch_insert() on leaf pages */
+	Assert(!P_ISLEAF(opaque) || key->scantid == NULL);
+
 	low = P_FIRSTDATAKEY(opaque);
 	high = PageGetMaxOffsetNumber(page);