Excerpts from Tom Lane's message of vie oct 28 15:37:43 -0300 2011: > The main concern I had about detoast before caching is the risk of > circularity, ie, needing detoastable cache entries in order to figure > out how to detoast. But I think it's probably okay. The current list > of catalogs with toast tables is > > pg_attrdef > pg_constraint > pg_database > pg_db_role_setting > pg_description > pg_proc > pg_rewrite > pg_seclabel > pg_shdescription > pg_statistic > pg_trigger > > Of these, only pg_proc is even conceivably consulted during a toast > table fetch, and we can be sure that functions needed for such a fetch > don't have toasted entries. But we will have to be very wary of any > future proposal for adding a toast table to pg_class, pg_index, etc.
BTW we had previous discussions about dropping pg_database's toast table. Maybe this is a good time to do it, even if there's no risk of this bug (or the hypothetical circularity detoasting problem) showing up there. -- Álvaro Herrera <alvhe...@commandprompt.com> The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers