Re: Choice of bitmap scan over index scan

Mathieu De Zutter  wrote:

You didn't include any information on your hardware and OS, which can
be very important.  Also, what version of PostgreSQL is this?
SELECT version(); output would be good.

> How can I make pgsql realize that it should always pick the index
> scan?

That would probably be a very bad thing to do, in a general sense.
I'm not even convinced yet it's really what you want in this case.

> shared_buffers = 24MB
> work_mem = 8MB
> #effective_cache_size = 128MB

Those are probably not optimal; however, without information on your
hardware and runtime environment, I can't make any concrete
suggestion.

> #seq_page_cost = 1.0
> #random_page_cost = 4.0

It's entirely possible that you will get plans more appropriate to
your hardware and runtime environment by adjusting these.  Again, I
lack data to propose anything specific yet.

-Kevin