"Albe Laurenz" <laurenz.a...@wien.gv.at> wrote: > If your query involves foreign scans on two foreign tables on the > same foreign server, these should always see the same snapshot, > because that's how it works with two scans in one query on local > tables. That makes sense. > So I think it should be REPEATABLE READ in all cases - > SERIALIZABLE is not necessary as long as all you do is read. That depends on whether you only want to see states of the database which are consistent with later states of the database and any invariants enforced by triggers or other software. See this example of how a read-only transaction can see a bogus state at REPEATABLE READ or less strict transaction isolation: http://wiki.postgresql.org/wiki/SSI#Read_Only_Transactions Perhaps if the transaction using the pgsql_fdw is running at the SERIALIZABLE transaction isolation level, it should run the queries at the that level, otherwise at REPEATABLE READ. -Kevin
-- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
