From: Tomas Vondra <tomas.vondra@postgresql.org>
Date: Fri, 7 May 2021 20:29:43 +0000 (+0200)
Subject: Copy the INSERT query in postgres_fdw
X-Git-Tag: REL_14_BETA1~64
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c6a01d924939306e95c8deafd09352be6a955648;p=thirdparty%2Fpostgresql.git

Copy the INSERT query in postgres_fdw

When executing the INSERT with batching, we may need to rebuild the
query when the batch size changes, in which case we pfree the current
string. We must not release the original string, stored in fdw_private,
because that may be needed in EXPLAIN ANALYZE. So make copy of the SQL,
but only for INSERT queries.

Reported-by: Pavel Stehule
Discussion: https://postgr.es/m/CAFj8pRCL_Rjw-MCR6J7VX9OF7MR6PA5K8qUbrMvprW_e-aHkfQ%40mail.gmail.com
---

diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index 8bcdc8d6160..4ff58d9c275 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -3903,7 +3903,10 @@ create_foreign_modify(EState *estate,
 	/* Set up remote query information. */
 	fmstate->query = query;
 	if (operation == CMD_INSERT)
+	{
+		fmstate->query = pstrdup(fmstate->query);
 		fmstate->orig_query = pstrdup(fmstate->query);
+	}
 	fmstate->target_attrs = target_attrs;
 	fmstate->values_end = values_end;
 	fmstate->has_returning = has_returning;