Skip site navigation (1) Skip section navigation (2)

Re: Trying to track down weird query stalls

From: dan(at)sidhe(dot)org
To: "Alvaro Herrera" <alvherre(at)commandprompt(dot)com>
Cc: dan(at)sidhe(dot)org,"Robert Haas" <robertmhaas(at)gmail(dot)com>, "Scott Marlowe" <scott(dot)marlowe(at)gmail(dot)com>, pgsql-performance(at)postgresql(dot)org
Subject: Re: Trying to track down weird query stalls
Date: 2009-03-30 21:07:36
Message-ID: 51413.199.172.169.17.1238447256.squirrel@localhost (view raw or flat)
Thread:
Lists: pgsql-performance
> dan(at)sidhe(dot)org escribió:
>> > dan(at)sidhe(dot)org escribió:
>> >
>> >> where libinstance.libdate <= 1238445044
>> >>    and libinstance.enddate > 1238445044
>> >>    and libinstance.libinstanceid = libobject.libinstanceid
>> >>    and libinstance.architecture = ?
>> >
>> > How are you generating the explain?  My bet is that you're just
>> > substituting a literal in the architecture condition, but if the
>> driver
>> > is smart then maybe it's preparating the query beforehand.  You'll get
>> a
>> > different plan in that case.
>>
>> I don't think so. Perl's DBI is involved, but the statement's in a
>> variable.
>
> So what's the "?" in the query you pasted earlier?

The first ? (for architecture) is 1, the second ? (for branchid) is 0.
They both should get passed to Postgres as $1 and $2, respectively,
assuming DBD::Pg does its substitution right. (They're both supposed to go
in as placeholders)

-Dan

In response to

Responses

pgsql-performance by date

Next:From: Alvaro HerreraDate: 2009-03-30 21:22:39
Subject: Re: Trying to track down weird query stalls
Previous:From: Alvaro HerreraDate: 2009-03-30 21:00:22
Subject: Re: Trying to track down weird query stalls

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group