From: Tom Lane <tgl@sss.pgh.pa.us>
To: Laurenz Albe <laurenz.albe@cybertec.at>
cc: "James Pang (chaolpan)" <chaolpan@cisco.com>,
        "pgsql-admin@lists.postgresql.org" <pgsql-admin@lists.postgresql.org>
Subject: Re: database collation "C" and "C.LATIN1"
In-reply-to: <5a8c87da0b8b61afd6ce12bb5cd37e87227dc7f1.camel@cybertec.at>
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Comments: In-reply-to Laurenz Albe <laurenz.albe@cybertec.at>
	message dated "Thu, 09 Mar 2023 13:04:34 +0100"
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Date: Thu, 09 Mar 2023 09:35:49 -0500
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Laurenz Albe <laurenz.albe@cybertec.at> writes:
> On Thu, 2023-03-09 at 08:37 +0000, James Pang (chaolpan) wrote:
>> Both follow  "C"  collate behavior ,right?  

> Right.

There is another difference: "C" is a built-in collation, while
"C.latin1" must have been something that initdb made because
"locale -a" claimed it exists on your platform.  Postgres has
some optimizations built in for "C" (and its equivalent "POSIX")
that will not apply for "C.latin1".  So while they should be
behaviorally the same, "C.latin1" is likely to be slower.

			regards, tom lane