On Thu, Apr 14, 2016 at 1:01 PM, Andres Freund <and...@anarazel.de> wrote: > On 2016-04-14 13:16:20 +0200, Andreas Karlsson wrote: >> I am personally not a fan of the pg_get_Xdef() functions due to their heavy >> reliance on the syscache which feels rather unsafe in combination with >> concurrent DDL. > > I'm not sure I find that convincing: The state portrayed by the syscache > is th state COPY/SELECT et al will be using. I think the angle to > attack this is rather to allow blocking 'globally visible' DDL > efficiently and correctly, rather than the hack pg_dump is using right now.
Maybe. I think that idea of changing the pg_get_Xdef() stuff to use the transaction snapshot rather than the latest snapshot might be worth considering, too. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers