Re: Index Scans become Seq Scans after VACUUM ANALYSE

Luis Alberto Amigo Navarro wrote:
> Hi All.
> I've been reading all the thread and I want to add a few points:
>
> You can set enable_seqscan=off in small or easy queries, but in large
> queries index can speed parts of the query and slow other, so I think it is
> neccesary if you want Postgres to become a Wide-used DBMS that the planner
> could be able to decide accuratelly, in the thread there is a point that
> might be useful, it will be very interesting that the planner could learn
> with previous executions, even there could be a warm-up policy to let
> planner learn about how the DB is working, this info could be stored with DB
> data, and could statistically show how use of index or seqscan works on
> every column of the DB.

Yes, I have always felt it would be good to feed back information from
the executor to the optimizer to help with later estimates. Of course,
I never figured out how to do it. :-)

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