From: Frits Hoogland <frits.hoogland@gmail.com>
Content-Type: multipart/alternative;
	boundary="Apple-Mail=_AAF48DB1-196D-464F-B2C6-FE78AEE4579F"
Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.300.87.4.3\))
Subject: Any risk or overhead considerations for frequently executing queries
 against catalog tables?
Message-Id: <F3953D11-A866-49CE-80C3-F00469A2521A@gmail.com>
Date: Sat, 25 Jan 2025 12:23:32 +0100
To: pgsql-performance@lists.postgresql.org
Archived-At: 
 <https://www.postgresql.org/message-id/F3953D11-A866-49CE-80C3-F00469A2521A%40gmail.com>
Precedence: bulk


--Apple-Mail=_AAF48DB1-196D-464F-B2C6-FE78AEE4579F
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
	charset=us-ascii

For monitoring database behaviour and trying to build an history of =
activity, if I would create an application that creates a single =
connection and execute something like:
select * from pg_stat_activity;
select * from pg_stat_database;
select * from pg_stat_bgwriter;
select * from pg_stat_wal;
select * from pg_settings;
select * from pg_database;
For which the query is prepared, and execute that every 1 second, would =
there be any realistic danger or overhead that should be considered?
My thinking is that the data for these catalogs are all in shared memory =
and when executed serially and do not cause any significant resources to =
be taken?

Thanks,

Frits Hoogland


--Apple-Mail=_AAF48DB1-196D-464F-B2C6-FE78AEE4579F
Content-Transfer-Encoding: 7bit
Content-Type: text/html;
	charset=us-ascii

<html><head><meta http-equiv="content-type" content="text/html; charset=us-ascii"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">For monitoring database behaviour and trying to build an history of activity, if I would create an application that creates a single connection and execute something like:<div>select * from pg_stat_activity;</div><div>select * from pg_stat_database;</div><div>select * from pg_stat_bgwriter;</div><div>select * from pg_stat_wal;</div><div>select * from pg_settings;</div><div>select * from pg_database;</div><div>For which the query is prepared, and execute that every 1 second, would there be any realistic danger or overhead that should be considered?</div><div>My thinking is that the data for these catalogs are all in shared memory and when executed serially and do not cause any significant resources to be taken?</div><div><br></div><div>Thanks,</div><div><br></div><div><div>
<div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><b>Frits Hoogland</b></div><div><br></div></div><br class="Apple-interchange-newline"><br class="Apple-interchange-newline">

</div>

<br></div></body></html>
--Apple-Mail=_AAF48DB1-196D-464F-B2C6-FE78AEE4579F--