Re: Nested Loop join being improperly chosen

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Aug 28, 2008, at 6:01 PM, David Rowley wrote:

I had a similar problem here:
http://archives.postgresql.org/pgsql-bugs/2008-07/msg00026.php

Is the nested loop performing a LEFT join with yours? It's a little
difficult to tell just from the query plan you showed.

A work around for mine was to use a full outer join and eliminate the extra rows in the where clause. A bit of a hack but it changed a 2 min query into
one that ran in under a second.

Of course this is not helping with your problem but at least may trigger
some more feedback.

Hi David,
Thanks for your input. All of the joins are inner joins; the query is a large one with 5 or 6 subqueries. It was being generated from a popular data warehousing / business intelligence product whose name I shall not mention. The vendor ended up pulling the subselects out into SELECT INTO statements on temporary tables. It's kludgey, but it works much better.

Thanks,
Brad

Attachment: smime.p7s
Description: S/MIME cryptographic signature


[Postgresql General]     [Postgresql PHP]     [PHP Users]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Yosemite]

  Powered by Linux