Arctic Toucan wrote: > > I have a heavily partitioned DW type database that has over 5,000 > tables in it. Data is only ever inserted, read and then truncated > after some period of time. Once the table is truncated, the > constraints are changed and the table is reused. This works well until > Postgres hits the autovacuum_freeze_max_age, which I currently have > set @ 1billion). Since these tables are only ever inserted to and > truncated, they are not normally vacuumed(which is what I want, since > data is typically going to be truncated before needing to be > vacuumed).
AFAICS this should be safe. In fact, in 8.3 TRUNCATE advances relfrozenxid. (Perhaps you should consider upgrading if possible.) > UPDATE pg_class SET relfrozenxid = ( select relfrozenxid from pg_class > where age(relfrozenxid) in (select min(age(relfrozenxid)) from > pg_class where relkind = 'r') limit 1) WHERE relname = '<table being > truncated>'; Tou could just obtain the xid of the transaction that's going to do the import (for example by creating a temp table and getting it's xmin from pg_class) -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-admin mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
