Re: Simple Query not using Primary Key Index

In general, I do not understand why a PK index should not be used when the
query can be satisfied by the index itself. Can anyone give some reason to
this?

On Mon, Feb 6, 2017, 6:29 PM Aron Podrigal <aronp(at)guaranteedplus(dot)com> wrote:

> EXPLAIN ANALYZE does not tell me much. It doesn't say why the planner opts
> for not using the Primary key index.
>
> On Mon, Feb 6, 2017, 6:23 PM Alban Hertroys <haramrae(at)gmail(dot)com> wrote:
>
>
> > On 7 Feb 2017, at 0:16, Podrigal, Aron <aronp(at)guaranteedplus(dot)com> wrote:
> >
> > Hi,
> >
> > I noticed when I do a simple SELECT id FROM mytable WHERE id =
> 'cb81d070-4213-465f-b32e-b8db43b83a25'::UUID Postgres does not use the
> primary key index and opts for a Seq Scan.
> >
> > I of course did VACUUM ANALYZE and I have reset statistics But no sign.
> Is there any particular thing I should be looking at?
>
> An EXPLAIN ANALYZE would be a good start.
>
> Alban Hertroys
> --
> If you can't see the forest for the trees,
> cut the trees and you'll find there is no forest.
>
>