Hi I'm a postgres novice so .... I have this fairly simple table ------------------------------------------------- device integer not null, group integer not null, datum timestamp without time zone not null, val1 numeric(7,4) not null default 0.000, val2 numeric(7,4) not null default 0.000 ------------------------------------------------- The device column is a foreign-key to the PK of my device table. and I have a UNIQUE INDEX on 3 columns device, group, datum This is just a test database and I want to keep the "datum" values (timestamps that span approx 1 month) all bound to CURRENT_DATE(). So I thought I’d just run this once (via cron) every morning. BEGIN; DROP INDEX data_unique; UPDATE data SET datum = (data.datum + interval '24 hours'); CREATE UNIQUE INDEX data_unique ON public.data USING BTREE (device, group, datum); COMMIT; But 1. it’s taking forever and 2. I’m seeing that my disk is filling up real fast. Any suggestions? Alan -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance