John Sidney-Woollett <johnsw@wardbrook.com> writes:
> I can restore the file system backup of pgsql/data to another database
> server and then get the info from pg_database. Or I can import a dump
> file from 15 minutes before I re-inited the database...
Importing a dump will tell you nothing at all, as all the data will be
freshly loaded.
> What exactly am I looking for though?
SELECT datname, age(datfrozenxid) FROM pg_database;
where the second column approaches 2 billion.
Alternatively, wait a few weeks and note which entries in your live
database are increasing rather than staying near 1 billion.
regards, tom lane
