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Re: Planner regression in 9.1: min(x) cannot use partial index with NOT NULL - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Planner regression in 9.1: min(x) cannot use partial index with NOT NULL
Date
Msg-id 20968.1300717529@sss.pgh.pa.us
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In response to Re: Planner regression in 9.1: min(x) cannot use partial index with NOT NULL  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Planner regression in 9.1: min(x) cannot use partial index with NOT NULL
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Robert Haas <robertmhaas@gmail.com> writes:
> On Mon, Mar 21, 2011 at 7:17 AM, Marti Raudsepp <marti@juffo.org> wrote:
>> I know that the Merge Append patch required some changes in the
>> min/max optimization, which is probably the cause.

> Yeah, I think this is a direct result of commit
> 034967bdcbb0c7be61d0500955226e1234ec5f04.

Yeah, looks that way.  I'm not sure what it would take to re-support
this case without losing the other advantages of the change.  Personally
I'm not terribly excited about it: I don't think that suppressing nulls
from an index this way is really very useful.  Using a partial index
probably eats more planner cycles than you'll save, overall.
        regards, tom lane

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