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Re: PostgreSQL Limits: maximum number of columns in SELECT result

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Dave Cramer <davecramer@postgres.rocks>, Amul Sul <sulamul@gmail.com>, Vladimir Sitnikov <sitnikov.vladimir@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-05-31T18:15:14Z
Lists: pgsql-hackers 
On 2022-May-31, Tom Lane wrote:

> Detail is far from "free".  Most readers are going to spend more time
> wondering what the difference is between "columns per table" and "columns
> per tuple", and which limit applies when, than they are going to save by
> having the docs present them with two inconsistent numbers.

I think it's reasonable to have two adjacent rows in the table for these
two closely related things, but rather than "columns per tuple" I would
label the second one "columns in a result set".  This is easy enough to
understand and to differentiate from the other limit.

(Replacing "in a" with "per" sounds OK to me but less natural, not sure
why.)

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/
"The Gord often wonders why people threaten never to come back after they've
been told never to return" (www.actsofgord.com)

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  1. Doc: mention limitation of the number of resultset columns