> We have a pretty big database that is going for an upgrade (PG7 -> PG8) > in the next few days, we have tested all the features of our application > but we cannot be sure that everything will work out perfectly (db is > managing several blob's only tables that have proven to be pretty hard > to configure). > I am currently investigating a worst-case-scenario strategy that would > be to downgrade the database from PG8 to 7 if anything goes wrong;00 > this implies that we: > 1) dump from a running PG8 > 2) remove PG8 and reinstall PG7 > 3) restore the dump into the running PG7 > > unfortunately pg_restore complains about the dump header and doesn't > restore the db at all, having tried to dump with both -Ft and -Fc flags > > shall I try the "--ignore-version" option in pg_restore? > is there going to be any problem in using this option? (corrupted data, > tables, etc.) My understanding is that dumps are not backwards compatible. Any dumps created with a Version 8.* pg_dump cannot be used for any older versions. If you want "play it safe" you should create a new server for the postgresql version 8.1 to preform validation tests with your front-ends. After you are satisfied that everything works well you can replace the version 7 production server with version 8. If you would like a safety net beyond this you could contact one of the PostgreSQL consulting companies to walk you through the integration of V.8.1 into your projection system. Regards, Richard Broersma Jr.
