After resetting all statistics it still opts for a Seq Scan. I went ahead to test with creating another table and querying that, and it shows on that test table to be using the index. So I wonder if there is anything else that may effect the planner. is there a way I can dog into this and see the steps the planner performs while deciding which ap to use?
Thanks!
On 2/6/17, Podrigal, Aron <aronp@guaranteedplus.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?
Postgres uses specified access methods according to table's statistics.
If you have a small table, it is likely that Postgres uses SeqScan
because it is similar or cheaper than IndexScan. That's why it can
ignore existing indexes.
--
Best regards,
Vitaly Burovoy