2010/9/30 Pavel Stehule <pavel.stehule@xxxxxxxxx>: > Hello > > 2010/9/30 Tom Lane <tgl@xxxxxxxxxxxxx>: >> Vincenzo Romano <vincenzo.romano@xxxxxxxxxxx> writes: >>> create or replace function session_init() >>> returns void >>> language plpgsql >>> as $body$ >>> declare >>> Â t text; >>> begin >>> Â select valu into t from session where name='SESSION_ID'; >>> Â if not found then >>> Â Â create temporary table session ( like public.session including all ); >>> Â Â insert into session values ( 'SESSION_ID',current_user ); >>> Â end if; >>> end; >>> $body$; >> >>> The idea is to create a temporary table to store session variables >>> only of there's no temporary table with that name. >> >> That isn't going to work tremendously well. Âplpgsql will cache a plan >> for that SELECT on first use, and creation of the temp table is not an >> event that will cause replanning of a select that doesn't already use >> the temp table. >> > > I found a little bit faster solution a catching a exception. > > http://okbob.blogspot.com/2008/11/plpgsql-and-temp-tables.html Hmmm ... do you think the performance would be the same in v9? > but if you need a session variables, then you can use a plperl > > http://www.postgresql.org/docs/9.0/static/plperl-global.html I will look into this. What I need is a set of variable for each connection. > Regards > > Pavel Stehule Anyway, I'm quite puzzled by the fact that an EXCEPTION WHEN can be faster than an IF .. THEN .. ELSE with a rather simple test. Unless the pg_table_is_visible() is really bad. Thanks a lot. -- Vincenzo Romano at NotOrAnd Information Technologies Software Hardware Networking Training Support Security -- NON QVIETIS MARIBVS NAVTA PERITVS -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
