From 5b86fedfb57ea943f883a13c6d50c5a9e2a1cc57 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 22 Mar 2013 17:22:31 -0400 Subject: Document cross-version compatibility issues for contrib/postgres_fdw. One of the use-cases for postgres_fdw is extracting data from older PG servers, so cross-version compatibility is important. Document what we can do here, and further annotate some of the coding choices that create compatibility constraints. In passing, remove one unnecessary incompatibility with old servers, namely assuming that we didn't need to quote the timezone name 'UTC'. --- contrib/postgres_fdw/postgres_fdw.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'contrib/postgres_fdw/postgres_fdw.c') diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index 687b87b8604..49dfe2c5edb 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -801,6 +801,9 @@ postgresGetForeignPlan(PlannerInfo *root, * The extra roundtrips involved in trying to duplicate the local * semantics exactly don't seem worthwhile (see also comments for * RowMarkType). + * + * Note: because we actually run the query as a cursor, this assumes that + * DECLARE CURSOR ... FOR UPDATE is supported, which it isn't before 8.3. */ if (baserel->relid == root->parse->resultRelation && (root->parse->commandType == CMD_UPDATE || -- cgit v1.2.3