Ensure relcache consistency around generated columns

petere · petere · commit fc7a5e9eaa2f · 2020-02-06T21:25:01.000+01:00
In certain transient states, it's possible that a table has attributes with attgenerated set but no default expressions in pg_attrdef yet. In that case, the old code path would not set relation->rd_att->constr->has_generated_stored, unless relation->rd_att->constr was also populated for some other reason. There was probably no practical impact, but it's better to keep this consistent. Reported-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/flat/20200115181105.ad6ab6dlgyww3lb6%40alap3.anarazel.de
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
@@ -669,8 +669,11 @@ RelationBuildTupleDesc(Relation relation)
 	/*
 	 * Set up constraint/default info
 	 */
-	if (constr->has_not_null || ndef > 0 ||
-		attrmiss || relation->rd_rel->relchecks)
+	if (constr->has_not_null ||
+		constr->has_generated_stored ||
+		ndef > 0 ||
+		attrmiss ||
+		relation->rd_rel->relchecks)
 	{
 		relation->rd_att->constr = constr;
 
