Thread: Lowering temp_buffers minimum

Hi,

I am working on writing some tests for temporary tables. One of the tests is
that we correctly handle running out of buffer pins. That's a bit more
annoying than it needs to because the minimum for temp_buffers is 100.

It seems rather odd that our minimum for temp_buffers is 100 while the minimum
for shared_buffers, which is shared across connections!, is 16.

Does anybody see a reason we shouldn't lower temp_buffers to match
shared_buffers?

Greetings,

Andres Freund

Hi,

On 2025-02-25 09:33:36 -0500, Andres Freund wrote:
> I am working on writing some tests for temporary tables. One of the tests is
> that we correctly handle running out of buffer pins. That's a bit more
> annoying than it needs to because the minimum for temp_buffers is 100.
> 
> It seems rather odd that our minimum for temp_buffers is 100 while the minimum
> for shared_buffers, which is shared across connections!, is 16.
> 
> Does anybody see a reason we shouldn't lower temp_buffers to match
> shared_buffers?

FWIW, here's a set of patches adding some testing for temp table corner cases
that aren't currently hit, even in master. They work with temp_buffers = 100,
but would require a smaller table if a lower minimum .  And indeed the test
would currently fail without the preceding commits I included, which are from

  https://www.postgresql.org/message-id/CA%2BhUKGK_%3D4CVmMHvsHjOVrK6t4F%3DLBpFzsrr3R%2BaJYN8kcTfWg%40mail.gmail.com

Greetings,

Andres Freund