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 Mon, Feb 6, 2017, 6:33 PM Vitaly Burovoy <vitaly.buro...@gmail.com> wrote: > On 2/6/17, Podrigal, Aron <ar...@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 >
