From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jim Nasby <Jim.Nasby@BlueTreble.com>
Cc: Anton Melser <melser.anton@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Plan differences
Date: Thu, 31 Dec 2015 12:11:15 -0500
Message-ID: <14868.1451581875@sss.pgh.pa.us> (raw)
In-Reply-To: <568557D6.8040905@BlueTreble.com>
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Jim Nasby <Jim.Nasby@BlueTreble.com> writes:
> On 12/31/15 9:02 AM, Tom Lane wrote:
>> If you don't want to rebuild the whole database, you can create indexes to
>> support this by declaring them with COLLATE "C", or the older way is to
>> declare them with text_pattern_ops as the index opclass.
> Do you have to do anything special in the query itself for COLLATE "C"
> to work?
No.
> I didn't realize the two methods were equivalent.
Well, they're not equivalent exactly, but indxpath.c knows that either
way produces an index that will work for LIKE.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, Jim.Nasby@BlueTreble.com, melser.anton@gmail.com
Subject: Re: Plan differences
In-Reply-To: <14868.1451581875@sss.pgh.pa.us>
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