From: Tom Lane <tgl@sss.pgh.pa.us>
To: Grega Jesih <Grega.Jesih@actual-it.si>
cc: "David G. Johnston" <david.g.johnston@gmail.com>,
        "grega.jesih@gmail.com" <grega.jesih@gmail.com>,
        Pg Docs <pgsql-docs@lists.postgresql.org>
Subject: Re: text fields and performance for ETL
In-reply-to: <c57e7a702932465ca9962d4f5d332c3a@actual-it.si>
References: <163594615980.678.1904941309603792278@wrigleys.postgresql.org>
 <CAKFQuwa_02fEtL8zJMt7MR=xvrp-De1pQtHFtg7fSHhSm1ajnA@mail.gmail.com>
 <686716cb5c4242c28e5967d9b6fcfc75@actual-it.si>,<137264.1635961048@sss.pgh.pa.us>
 <c57e7a702932465ca9962d4f5d332c3a@actual-it.si>
Comments: In-reply-to Grega Jesih <Grega.Jesih@actual-it.si>
	message dated "Wed, 03 Nov 2021 18:09:28 -0000"
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Date: Wed, 03 Nov 2021 14:50:47 -0400
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Grega Jesih <Grega.Jesih@actual-it.si> writes:
> It matters a lot. It means time saving. Plenty of time. So we're talking=
 performance. Not postgres performance, interface performance.

One more time: our docs are here to explain Postgres performance.
It is very easy to show that char/varchar are strictly worse than
text so far as Postgres is concerned.  Other tools need to document
their own performance considerations in their own docs.

Now, if you have a *semantic* consideration, like "a state abbreviation
should be exactly two characters", those datatypes might help you
with enforcing that.  But that's not a performance consideration.

			regards, tom lane