From: Achilleas Mantzios <a.mantzios@cloud.gatewaynet.com>
To: pgsql-admin@lists.postgresql.org
Subject: Re: Index file is growing when I drop a table. Why?
Date: Thu, 16 Nov 2023 19:22:20 +0200
Message-ID: <810a0a70-0fbc-400c-bc67-f9d627f103be@cloud.gatewaynet.com> (raw)
In-Reply-To: <CANzqJaBZLxdF+057oKo468nu7nq0jr+6tyOcTM-P6Cy+3kh3jQ@mail.gmail.com>
References: <CANzqJaBZLxdF+057oKo468nu7nq0jr+6tyOcTM-P6Cy+3kh3jQ@mail.gmail.com>
Στις 16/11/23 18:32, ο/η Ron Johnson έγραψε:
> Pg 15.4
>
> I'm dropping the large table "bar" in a test database, and it's taking
> a /long/ time. Thus, I thought I'd watch it deleting files.
>
> To my surprise, though, the files that store the index are growing.
> What's up with that?
What does pg_locks show ?
SELECT blocked_locks.pid AS blocked_pid,
blocked_activity.usename AS blocked_user,
blocking_locks.pid AS blocking_pid,
blocking_activity.usename AS blocking_user,
blocked_activity.query AS blocked_statement,
blocking_activity.query AS blocked_by
FROM pg_locks blocked_locks
JOIN pg_stat_activity blocked_activity ON blocked_activity.pid =
blocked_locks.pid
JOIN pg_locks blocking_locks ON blocking_locks.locktype =
blocked_locks.locktype AND NOT blocking_locks.database IS DISTINCT FROM
blocked_locks.database
AND NOT blocking_locks.relation IS DISTINCT FROM blocked_locks.relation
AND NOT blocking_locks.page IS DISTINCT FROM blocked_locks.page AND NOT
blocking_loc
ks.tuple IS DISTINCT FROM blocked_locks.tuple AND NOT
blocking_locks.virtualxid IS DISTINCT FROM blocked_locks.virtualxid AND
NOT blocking_locks.transactioni
d IS DISTINCT FROM blocked_locks.transactionid AND NOT
blocking_locks.classid IS DISTINCT FROM blocked_locks.classid AND NOT
blocking_locks.objid IS DISTINCT
FROM blocked_locks.objid AND NOT blocking_locks.objsubid IS DISTINCT
FROM blocked_locks.objsubid AND blocking_locks.pid <> blocked_locks.pid
JOIN pg_stat_activity blocking_activity ON blocking_activity.pid =
blocking_locks.pid
WHERE NOT blocked_locks.granted;
>
> foo=# select * from pg_class where oid = 41533;
> -[ RECORD 1 ]-------+----------
> oid | 41533
> relname | i_bar_su1
> relnamespace | 2200
>
> $ pwd
> /var/lib/pgsql/15/data/base/16482
> $ la -aFl 41533*
> -rw------- 1 postgres postgres 1073741824 2023-11-16 11:15:06 41533
> -rw------- 1 postgres postgres 189792256 2023-11-16 11:24:15 41533.1
>
> Five minutes later, 41533.1 is 4.3MB larger.
>
> $ dir 41533*
> -rw------- 1 postgres postgres 1073741824 2023-11-16 11:15:06 41533
> -rw------- 1 postgres postgres 194101248 2023-11-16 11:29:44 41533.1
>
--
Achilleas Mantzios
IT DEV - HEAD
IT DEPT
Dynacom Tankers Mgmt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-admin@postgresql.org
Cc: a.mantzios@cloud.gatewaynet.com, pgsql-admin@lists.postgresql.org
Subject: Re: Index file is growing when I drop a table. Why?
In-Reply-To: <810a0a70-0fbc-400c-bc67-f9d627f103be@cloud.gatewaynet.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox