[PDO/PGSQL] Add an option that disables sending DEALLOCATE

[lucaspouzac]

Description

As explained on pgbouncer issue #991, it's not possible to use prepared statement cache of pgbouncer with PDO, because PDO send DEALLOCATE pdo_stmt_..

Adding an option to disable DEALLOCATE sending would allow pgbouncer to be used in transaction mode with its prepared statement cache.

May be the opportunity to use PQclosePrepared instead of DEALLOCATE. (Note: This will only be released in libpq 17) ?

[devnexen]

Good suggestion, might give a try once the 17 branch is, at least, under more stable state (release in 9 months-ish if I m not mistaken).

[JelteF]

To be clear PQclosePrepared would be the best future solution. But for now, while that is not available, at least having a way to turn off sending DEALLOCATE queries would make PDO work with PgBouncer its prepared statement support.

[lucaspouzac]

Yes, there is the same problem with PGcat

[devnexen]

Yes, there is the same problem with PGcat

is it this rust crate ?

[devnexen]

I see this "talks" directly postgresql language, ie not using any libpq wrapper or similar.

[JelteF]

I think @lucaspouzac that PDO is sending DEALLOCATE queries when using prepared statements is a problem for multiple connection poolers. i.e. Both PgBouncer and PGcat don't support DEALLOCATE queries in their prepared statement support. And I'm pretty sure Odyssey doesn't either.

So being able to turn them off would be useful to everyone that uses a connection pooler, not just if they are using PgBouncer.

[devnexen]

Looking at it, it might be possible to do without this new handy feature indeed.

[lucaspouzac]

Hi @devnexen, have you been able to test this functionality? Will this be included in a future version? Thanks.