On Mon, Nov 15, 2010 at 10:54 AM, Marti Raudsepp <ma...@juffo.org> wrote: > On Sun, Nov 14, 2010 at 02:16, Robert Haas <robertmh...@gmail.com> wrote: >> Here is a series of three patches related to unlogged tables. > > Just wondering, have you thought of any mechanisms how application > code might detect that an unlogged table was truncated due to restart? > While polling with something like "SELECT 1 FROM table LIMIT 1" might > work, it's an awful hack. > > One obvious use case for these unlogged tables would be materalized > views. I think it would be useful to execute e.g. a TRUNCATE trigger > so that an the view could be initialized. If an exclusive lock were > passed on to the trigger procedure, this could even be done in a > race-condition-free manner as far as I can tell. > > Would there be a problem with invoking this trigger from the session > that first touches the table?
Yeah, this infrastructure doesn't really allow that. The truncate happens way too early on in startup to execute any user-provided code. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
