In an academic setting, we have a couple of larger than typical Postgres databases. One for moodle is now 15GB and another for a research project is currently 24 GB. I notice while upgrading Postgresql in Debian from 8.3 to 8.4, the downtime on the 24 GB research database is extensive while using pg_upgradecluster It has now been 26 hours of downtime for the database, and about 18GB of the 24GB is recovered into the 8.4 destination so far. I read some of the tips on the Postgresql wiki on performance tweaks ( http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server ) and had implemented some improvements such as shared_buffers in the 8.3 instance prior to the upgrade. I thought if I was doing this again, I would have found the source postgresql.conf used by the pg_upgradecluster script for 8.4, and tuned it prior to the run. How do others manage larger database upgrades while minimizing downtime? Do you avoid pg_upgradecluster and simply do a pg_restore from a dump made prior to the upgrade? Do you run a replication and then resync it after the upgrade is complete? Googling for info on this I've only found remarks about it taking longer than you'd expect. -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
