Message-ID: <54994813530a36c0280fd8779e65ad1ad73d910a.camel@cybertec.at>
Subject: Re: a lot of session wait on lock relation
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: James Pang <jamespang886@gmail.com>,
	pgsql-performance@lists.postgresql.org
Date: Thu, 15 May 2025 14:08:05 +0200
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On Thu, 2025-05-15 at 16:27 +0800, James Pang wrote:
> PGv 15.10,=C2=A0 many session coming in doing "insert into tablexxx value=
s...." in parallel,
> this is a range partition tables, total 12 partitions plus one default pa=
rtition,
> only three btree indexes, no others constraints ,no foreign key. but we s=
ee hundreds
> of session waiting on "lock:relation", why inserts into partition table c=
ause "relation lock" ?

Something else does; use the pg_blocking_pids() function with the process I=
D of
a blocked backend to find out who is holding the lock.

If you have hundreds of sessions, you are allowing to many connections.

Yours,
Laurenz Albe