Re: select max(column) from parent table very slow - Mailing list pgsql-performance

From Tom Lane
Subject Re: select max(column) from parent table very slow
Date
Msg-id 18394.1156480407@sss.pgh.pa.us
Whole thread Raw
In response to Re: select max(column) from parent table very slow  ("Joshua D. Drake" <jd@commandprompt.com>)
Responses Re: select max(column) from parent table very slow
List pgsql-performance
"Joshua D. Drake" <jd@commandprompt.com> writes:
> Sriram Dandapani wrote:
>> Parent table has a column say column1 which is indexed (parent table and
>> all child tables are indexed on that column)

> In older versions of postgresql that would scan the whole table. In 8.1
> and above it doesn't. However, I am guess that since this is a
> partitioned table the planner isn't smart enough to just perform the
> query on each child and a max on the set that is returned.

It is not.  Feel free to submit a patch for planagg.c ...

            regards, tom lane

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