Message-ID: <509AC497.8070001@gmail.com>
Date: Wed, 07 Nov 2012 18:29:11 -0200
From: Rodrigo Rosenfeld Rosas <rr.rosas@gmail.com>
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To: Merlin Moncure <mmoncure@gmail.com>
CC: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-performance@postgresql.org
Subject: Re: Query completed in < 1s in PG 9.1 and ~ 700s in PG
 9.2
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Em 07-11-2012 14:34, Merlin Moncure escreveu:
> On Wed, Nov 7, 2012 at 5:16 AM, Rodrigo Rosenfeld Rosas
> <rr.rosas@gmail.com>  wrote:
>> Em 06-11-2012 19:11, Merlin Moncure escreveu:
>>
>>> On Tue, Nov 6, 2012 at 1:45 PM, Tom Lane<tgl@sss.pgh.pa.us>   wrote:
>>>> Rodrigo Rosenfeld Rosas<rr.rosas@gmail.com>   writes:
>>>>> Em 06-11-2012 17:24, Tom Lane escreveu:
>>>>>> Can you put together a self-contained test case to duplicate these
>>>>>> results?  I'm prepared to believe there's some sort of planner
>>>>>> regression involved here, but we'll never find it without a test case.
>>>>> I'd love to, but I'm afraid I won't have time to do this any time soon.
>>>>> Maybe on Sunday. I'll see if I can get a script to generate the database
>>>>> on Sunday and hope for it to replicate the issue.
>>>>> Would you mind if I coded it using Ruby? (can you run Ruby code in your
>>>>> computer?) I mean, for filling with some sample data.
>>>> No objection.
>>> hm, wouldn't timing the time to generate a raw EXPLAIN (that is,
>>> without ANALYZE) give a rough estimate of planning time?   better to
>>> rule it out before OP goes to the trouble...
>> This was a great guess! Congrats, Merlin:
> Heh -- that was tom's guess, not mine.  What this does is confirm the
> planner regression and that elevates the importance of Tom's request
> to get sample data so we (he) can fix it.

True, sorry :) So, thanks Tom! I have some good news. It seems I'll be 
able to send the schema after just stripping a few parts of the schema 
first.

Right now I have to leave but I think I'll have some time to do this 
tomorrow, so I hope I can send you the test case tomorrow.

As a curious note I tried running a query with 11 fields (instead of 14 
fields like in the example I gave you) and I didn't experience any 
problems...

Thank you very much you both!