Re: Deadlock bug
| От | Joel Jacobson |
|---|---|
| Тема | Re: Deadlock bug |
| Дата | |
| Msg-id | AANLkTikRLjqOV4u7C5RbfV+EekxKUMGy7hpO2N9XcynT@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Deadlock bug (Tom Lane <tgl@sss.pgh.pa.us>) |
| Список | pgsql-hackers |
Optimized away, check, OK, but why? Because there is no new data in the FK (table A) at the point of the first update of table B in process 2? But when process 1 updates A, the FK B->A points to new data, which leads to process 2 tries to acquire a sharelock, which is not granted due to the update of A?
--
Best regards,
Joel Jacobson
Glue Finance
E: jj@gluefinance.com
T: +46 70 360 38 01
Postal address:
Glue Finance AB
Box 549
114 11 Stockholm
Sweden
Visiting address:
Glue Finance AB
Birger Jarlsgatan 14
114 34 Stockholm
Sweden
2010/8/20 Tom Lane <tgl@sss.pgh.pa.us>
Joel Jacobson <joel@gluefinance.com> writes:> I fully agree it must obtain a sharelock on the FK, but I cannot understandIt *isn't* granted it the first time, because it doesn't try to acquire
> why it is granted it the first time, but not the second time?
it the first time. That FK check gets optimized away, while the second
one doesn't. Please reread what I said before.
regards, tom lane
--
Best regards,
Joel Jacobson
Glue Finance
E: jj@gluefinance.com
T: +46 70 360 38 01
Postal address:
Glue Finance AB
Box 549
114 11 Stockholm
Sweden
Visiting address:
Glue Finance AB
Birger Jarlsgatan 14
114 34 Stockholm
Sweden
В списке pgsql-hackers по дате отправления: