Re: Postgresql OOM
| От | Pantelis Theodosiou |
|---|---|
| Тема | Re: Postgresql OOM |
| Дата | |
| Msg-id | CAE3TBxxfzF3GpUz_tKF=+8fe0-9+C6M8Y01nnK8FpEFLtfe2WA@mail.gmail.com обсуждение исходный текст |
| Ответ на | Postgresql OOM (Radu Radutiu <rradutiu@gmail.com>) |
| Ответы |
Re: Postgresql OOM
Re: Postgresql OOM |
| Список | pgsql-hackers |
On Thu, Jun 6, 2024 at 1:25 PM Radu Radutiu <rradutiu@gmail.com> wrote:
Hello all,
I have a query that forces an out of memory error, where the OS will kill the postgresql process.
The query plan (run immediately after a vacuum analyze) is at https://explain.depesz.com/s/ITQI#html .
...
Any idea on how to identify the problem? I can reproduce it on demand. Should I report it pgsql-bugs?
Best regards,
Radu
I am not qualified to answer on the OOM issue but why are you joining the same table (outputrequest) 4 times (using an identical join condition)?
This essentially does a cross join, if an input_sequence value has say, 1000 related rows in outputrequest, you will be getting 1000^4 rows in the result set.
FROM inputrequest t LEFT JOIN outputrequest rec_tro ON rec_tro.input_sequence = t.input_sequence LEFT JOIN inputrequest r ON r.originalRequest_id = t.input_sequence LEFT JOIN outputrequest rpl_rec_tro ON rpl_rec_tro.input_sequence = r.input_sequence LEFT JOIN outputrequest rpl_snd_tro ON rpl_snd_tro.reply_input_sequence = r.input_sequence LEFT JOIN outputrequest snd_tro ON snd_tro.reply_input_sequence = t.input_sequence В списке pgsql-hackers по дате отправления: