Re: released savepoint blocking further statements - Mailing list pgsql-bugs

From Jeff Janes
Subject Re: released savepoint blocking further statements
Date
Msg-id CAMkU=1xA+9izwMjVzFVs9modUY5PmoJQdUEpL89DTbayyRAcAw@mail.gmail.com
Whole thread Raw
In response to released savepoint blocking further statements  (Miklós Fazekas <mfazekas@szemafor.com>)
Responses Re: released savepoint blocking further statements
List pgsql-bugs
On Thu, Apr 7, 2016 at 1:26 AM, Mikl=C3=B3s Fazekas <mfazekas@szemafor.com>=
 wrote:


> [2.] I've tried to use the query Lock Monitoring wiki from to find out wh=
at
> is blocking:
>
> it shows that 79469 | RELEASE SAVEPOINT active_record_2_47 is the
> current_statement_in_blocking_process.
>
> https://wiki.postgresql.org/wiki/Lock_Monitoring
>
> SELECT bl.pid                 AS blocked_pid,
>
>          a.usename              AS blocked_user,
>          ka.query               AS current_statement_in_blocking_process,
>          now() - ka.query_start AS blocking_duration,
>          kl.pid                 AS blocking_pid,
>          ka.usename             AS blocking_user,
>          a.query                AS blocked_statement,
>          now() - a.query_start  AS blocked_duration
>   FROM  pg_catalog.pg_locks         bl
>    JOIN pg_catalog.pg_stat_activity a  ON a.pid =3D bl.pid
>    JOIN pg_catalog.pg_locks         kl ON kl.transactionid =3D
> bl.transactionid AND kl.pid !=3D bl.pid
>    JOIN pg_catalog.pg_stat_activity ka ON ka.pid =3D kl.pid
>   WHERE NOT bl.GRANTED;


That is probably not the current statement in the blocking process.
It is likely that the blocking process is in the state "idle in
transaction", and the RELEASE SAVEPOINT is actually the most recent
statement, not the current statement.

I've updated the wiki to clarify that, but it could use some more polishing=
.

So your savepoint release has executed successfully, but the outer
transaction is still holding on to locks which block the other
process.  You have to convince that outer transaction to either commit
or rollback.

Cheers,

Jeff

pgsql-bugs by date:

Previous
From: Magnus Hagander
Date:
Subject: Re: [HACKERS] BUG #13854: SSPI authentication failure: wrong realm name used
Next
From: jacksonemmerich@gmail.com
Date:
Subject: BUG #14077: Error with pgadim v1.22.1 and ubuntu 15.10 + postgres 9.2