From: Jann Röder <roederja@ethz.ch>
To: pgsql-performance@postgresql.org
Subject: Re: Inefficient query plan
Date: Mon, 23 Aug 2010 12:15:43 +0200
Message-ID: <i4thof$gol$1@dough.gmane.org> (raw)
In-Reply-To: <AANLkTi=uFQ7saSbPUgK0hO2=e1MVQGenuLKOUU_+bvUM@mail.gmail.com>
References: <i4st4a$e8v$1@dough.gmane.org>
<AANLkTi=uFQ7saSbPUgK0hO2=e1MVQGenuLKOUU_+bvUM@mail.gmail.com>
Am 23.08.10 07:52, schrieb Scott Marlowe:
> Also are a.indexid and b.indexid the same type?
>
You mean ItemID? Fields of the same name are of the same type - so yes.
According to the documentation pgsql adds indexes for primary keys
automatically so (b.itemID, b.indexNumber) is indexed. Or do you think
adding an extra idnex for b.itemID alone will help? If I understand the
documentation correctly, pqSQL can use the first column of a
multi-column index as if it was indexed individually... but maybe I'm
wrong here.
>> I have two tables:
>> A: ItemID (PK), IsssueID (Indexed)
>> B: ItemID (FK), IndexNumber : PK(ItemID, IndexNumber)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: roederja@ethz.ch
Subject: Re: Inefficient query plan
In-Reply-To: <i4thof$gol$1@dough.gmane.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox