From: Tom Lane <tgl@sss.pgh.pa.us>
To: aditya desai <admad123@gmail.com>
cc: Pgsql Performance <pgsql-performance@lists.postgresql.org>
Subject: Re: Out of memory error
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Comments: In-reply-to aditya desai <admad123@gmail.com>
	message dated "Wed, 24 Nov 2021 10:57:37 +0530"
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Date: Wed, 24 Nov 2021 00:52:38 -0500
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aditya desai <admad123@gmail.com> writes:
> In a trigger function I am creating a temp table . When an update on a
> table is executed for say 10k rows. I get the below error.

> ERROR: out of shared memory
> HINT:You might need to increase max_locks_per_transaction
> CONTEXT: SQL Statement "created temp table changedinfo(colName
> varchar(100), oldValue varchar(4000), newValue varchar(4000)

[ raised eyebrow ... ]  If you are concerned about performance,
I'd start by not creating a temp table per row of the outer update.
That's costing probably 100x to 1000x as much as the row update itself.

			regards, tom lane