Re: bad estimates / non-scanning aggregates - Mailing list pgsql-performance

From Ken Geis
Subject Re: bad estimates / non-scanning aggregates
Date
Msg-id 3F4EC1D0.5010503@speakeasy.org
Whole thread Raw
In response to Re: bad estimates / non-scanning aggregates  (Bruno Wolff III <bruno@wolff.to>)
Responses Re: bad estimates / non-scanning aggregates  (Bruno Wolff III <bruno@wolff.to>)
List pgsql-performance
Bruno Wolff III wrote:
>>Not according to the optimizer!  Plus, this is not guaranteed to return
>>the correct results.
>
> For it to be fast you need an index on (stock_id, price_date) so that
> you can use an index scan.

I already said that such an index existed.  In fact, it is the primary
key of the table.  And yes, I *am* analyzed!

> The answers are guarenteed to be correct. See:
> http://developer.postgresql.org/docs/postgres/sql-select.html#SQL-DISTINCT

That's good to know.  Thanks!


Ken



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