Re: select function alias - Mailing list pgsql-general

From David G. Johnston
Subject Re: select function alias
Date
Msg-id CAKFQuwbGdznRrPqgqFjX4T5_KgH1HcLUBMmZ-N4hVRKVhdL6gQ@mail.gmail.com
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In response to Re: select function alias  ("btober@computer.org" <btober@broadstripe.net>)
Responses Re: select function alias  (Merlin Moncure <mmoncure@gmail.com>)
List pgsql-general
On Wed, Nov 30, 2016 at 8:15 AM, btober@computer.org <btober@broadstripe.net> wrote:
5. Use a CTE:

    with shortnames as (
        select to_char(impressions_create_date,'yyyy-mm-dd') as ymd from impressionsdb 
) select ymd from shortnames where ymd like '2016-11%';


​Except that WHERE clause won't get pushed down (I think...haven't checked an explain recently) so a sub-select is definitely better in this scenario.

David J.

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