> On Feb 9, 2024, at 10:00 AM, David Barron <david.barron@zencos.com> wrote: > > I’ve also seen references to copying over the pg_hba.conf and postgresql.conf files from the old data directory to the new.
Then you will be getting default values for the many, many parameters added to postgresql.conf between 11 & 15--and will have no explanatory entries documenting them. A much better suggestion is to diff the two, and apply customizations from the old to the new. (Also skim release notes for any that have been mooted.)
Alternatively, remove all default values from your PG11 postgresql.conf file. Then, when you copy it to the PG15 directory, you'll automatically get any default config values that have changed since PG 11.
And your postgresql.conf file will be much smaller.