RE: Commit with wait event on advisory lock!

Hi

I know very well advisory locks. The question is:

How a COMMIT statement could be blocked by a lock whatever the kind of the lock could be. COMMIT releases locks. How could it be blocked by a lock?!

Regards

Michel SALAIS

De : Rajesh Kumar <rajeshkumar(dot)dba09(at)gmail(dot)com>
Envoyé : mardi 21 janvier 2025 15:57
À : msalais(at)msym(dot)fr
Cc : pgsql-admin(at)lists(dot)postgresql(dot)org
Objet : Re: Commit with wait event on advisory lock!

Advisory locks are used by developers

On Tue, 21 Jan 2025, 20:18 , <msalais(at)msym(dot)fr <mailto:msalais(at)msym(dot)fr> > wrote:

Hi all,

I have long commits on a production database. To know why this happens I organized a snapshot system on table pg_stat_activity.

When I check the result I have this row in it:

postgres=# select * from public.fdj_ms_slow_stmts where pid = 2285947 \gx

-[ RECORD 1 ]----+-----------------------------------------------------------------------------------------------------------------------

datname | some_db

pid | 2285947

leader_pid |

usename | some_user

application_name | PostgreSQL JDBC Driver

backend_start | 2025-01-21 04:25:17.254477+01

xact_start | 2025-01-21 05:55:19.426945+01

query_start | 2025-01-21 05:55:19.428651+01

stmt_duration | 00:00:02.140691

tx_idle_duration | 00:00:00

ts_now | 2025-01-21 05:55:21.569342+01

state | active

wait_event_type | Lock

wait_event | advisory

query_id |

query | COMMIT

…

Is this possible ?

I am really surprised !

Michel SALAIS