Re: Big difference in time returned by EXPLAIN ANALYZE SELECT ... AND SELECT ...

From: Craig Ringer <craig(at)postnewspapers(dot)com(dot)au>
To: Vitalii Tymchyshyn <tivv00(at)gmail(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Big difference in time returned by EXPLAIN ANALYZE SELECT ... AND SELECT ...
Date: 2010-07-26 09:56:57
Message-ID: 4C4D5BE9.6040808@postnewspapers.com.au
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

On 26/07/10 17:25, Vitalii Tymchyshyn wrote:
> 26.07.10 12:15, Craig Ringer написав(ла):
>> On 26/07/10 16:35, Piotr Gasidło wrote:
>>
>>> Hello,
>>>
>>> I've found strange problem in my database (8.4.4, but also 9.0beta3,
>>> default postgresql.conf, shared_buffers raised to 256MB).
>>>
>>> EXPLAIN ANALYZE SELECT ...
>>> Total runtime: 4.782 ms
>>> Time: 25,970 ms

>> Given that, I'm wondering if the difference in this case is planning
>> time. I can't really imagine the query planner taking 20 seconds (!!) to
>> run, though, no matter how horrifyingly complicated the query and table
>> structure were, unless there was something going wrong.
>>
> Actually it's 20ms, so I suspect your point about planning time is correct.

Oh, a commas-as-fraction-separator locale.

That makes sense. Thanks for the catch.

--
Craig Ringer

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Piotr Gasidło 2010-07-26 10:04:13 Re: Big difference in time returned by EXPLAIN ANALYZE SELECT ... AND SELECT ...
Previous Message Matthew Wakeling 2010-07-26 09:47:14 Re: Testing Sandforce SSD