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	Tue, 7 May 2019 10:59:30 -0400
From: Tom Lane <tgl@sss.pgh.pa.us>
To: James Tomson <james@pushd.com>
cc: pgsql-bugs@lists.postgresql.org, Eric Jensen <ej@pushd.com>
Subject: Re: invalid memory alloc request size from pg_stat_activity?
In-reply-to: <1CFDCCD6-B268-48D8-85C8-400D2790B2C3@pushd.com>
References: <1CFDCCD6-B268-48D8-85C8-400D2790B2C3@pushd.com>
Comments: In-reply-to James Tomson <james@pushd.com>
	message dated "Mon, 06 May 2019 19:04:18 -0400"
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Date: Tue, 07 May 2019 10:59:30 -0400
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James Tomson <james@pushd.com> writes:
> We're upgrading from postgresql 9.6 to 10.6 and everything is working fi=
ne, but any query against pg_stat_activity results in ERROR:  invalid memo=
ry alloc request size 1652113408

> e.g:

> ourdb=3D> SELECT pid, state, age(query_start, clock_timestamp()), usenam=
e, query FROM pg_stat_activity WHERE query !=3D '<IDLE>' AND state !=3D 'i=
dle' ORDER BY age limit 100;
> ERROR:  invalid memory alloc request size 1652113408

That seems odd ...

> Maybe this has to do with us setting track_activity_query_size=3D102400?

It wouldn't surprise me if reading pg_stat_activity causes allocation of
track_activity_query_size * max_connections bytes, but unless you also
have max_connections set to some pretty insane value, that wouldn't
be enough to fit this observation.

Did you have these parameters set differently in 9.6?

			regards, tom lane