Re: Fastest way to clone schema ~1000x

On Mon, Feb 26, 2024 at 3:50 PM Daniel Gustafsson <daniel(at)yesql(dot)se> wrote:

> There is a measurable overhead in connections, regardless of if they are
> used
> or not. If you are looking to squeeze out performance then doing more over
> already established connections, and reducing max_connections, is a good
> place
> to start.
>

Clear, but with database-per-test (and our backend setup), it would have
been *great* if we could have switched database on the same connection
(similar to "USE xxx" in mysql). That would limit the connections to the
amount of workers, not multiplied by tests.

Even with a pooler, we're still going to be maintaining 1000s of
connections from the backend workers to the pooler. I would expect this to
be rather efficient, but still unnecessary. Also, both pgbouncer/pgpool
don't seem to support switching database in-connection (they could have
implemented the aforementioned "USE" statement I think!). [Additionally
we're using PHP that doesn't seem to have a good shared memory pool
implementation -- pg_pconnect is pretty buggy].

I'll continue with some more testing. Thanks for now!