Douglas McNaught <doug@xxxxxxxxxxxx> writes: > "Milen Kulev" <makulev@xxxxxxx> writes: >> I can not understand why pg_dump, pg_dumpall have hard-coded "template0" ? > The reason is this: any extra stuff that your database inherited from > template1 (or whatever template you used) will be dumped out as part > of your database. There is no way to for pg_dump to tell what parts > came from template1 and what parts were added afterward, so it bases > its dump on template0, which is a minimal database. If you based your > restored database on template1, you would get collisions as the > restore tried to add objects that were already there from template1. Not only that. If you changed template1 after creating your database from it, then a dump and restore of your database would be wrong if it used template1: it would produce a database that did not match what was dumped, but rather included those subsequent changes in template1. (Which might in fact be what you'd wish for, but it's not pg_dump's charter.) template0 is not only minimal but stable, so basing the restore relative to it is more likely to produce a matching database than using template1. regards, tom lane
