Re: Waiting for select

Marc Munro wrote:
> Can someone explain this? I seem to have a query which is being blocked
> by a lock. I was under the impression that selects are never blocked.
> Am I missing something or is this bad behaviour?

Do you happen to be running a vacuum full?

>
> I am using slony and am synchronising a slave for the first time. In
> the hope of seeing some progress on the slave I attempt to perform a
> select count(*) on one of the tables.
>
> The select just stops. ps shows this:
>
> postgres 5987 0.0 0.4 19180 4188 ? S 15:16 0:00 postgres: postgres testdb 192.168.1.111(33598) SELECT waiting
>
> A query of blocking locks shows this:
>
> object | trans | pid | mode | blocker
> ---------------------------+-------+------+---------------------+---------
> testdb.campaign_cost_pk | | 5754 | AccessShareLock |
> testdb.csn_log_pk | | 5754 | RowExclusiveLock |
> testdb.pg_trigger | | 5754 | AccessShareLock |
> testdb.pg_trigger | | 5754 | RowExclusiveLock |
> testdb.sl_subscribe | | 5754 | AccessShareLock |
> testdb.csn_log_idx2 | | 5754 | RowExclusiveLock |
> testdb.campaign | | 5754 | AccessShareLock |
> testdb.campaign | | 5754 | RowExclusiveLock |
> testdb.campaign | | 5754 | AccessExclusiveLock |
> testdb.pg_rewrite | | 5754 | AccessShareLock |
> testdb.pg_rewrite | | 5754 | RowExclusiveLock |
> testdb.computer_sn_log | | 5754 | AccessShareLock |
> testdb.computer_sn_log | | 5754 | RowExclusiveLock |
> testdb.computer_sn_log | | 5754 | AccessExclusiveLock |
> testdb.address_type_pk | | 5754 | AccessShareLock |
> testdb.campaign_pk | | 5754 | AccessShareLock |
> testdb.sl_log_1 | | 5754 | AccessShareLock |
> testdb.sl_log_1 | | 5754 | RowExclusiveLock |
> testdb.csn_cookie_idx1 | | 5754 | AccessShareLock |
> testdb.pg_index | | 5754 | AccessShareLock |
> testdb.pg_index | | 5754 | RowShareLock |
> testdb.csn_log_idx3 | | 5754 | RowExclusiveLock |
> testdb.csn_cookie_pk | | 5754 | AccessShareLock |
> testdb.sl_log_2 | | 5754 | AccessShareLock |
> testdb.sl_log_2 | | 5754 | RowExclusiveLock |
> testdb.sl_set | | 5754 | AccessShareLock |
> testdb.sl_set | | 5754 | RowShareLock |
> testdb.campaign_cost | | 5754 | AccessShareLock |
> testdb.campaign_cost | | 5754 | RowExclusiveLock |
> testdb.campaign_cost | | 5754 | AccessExclusiveLock |
> testdb.sl_table | | 5754 | AccessShareLock |
> testdb.sl_table | | 5754 | RowShareLock |
> testdb.sl_table | | 5754 | RowExclusiveLock |
> | 9182 | 5754 | ExclusiveLock |
> testdb.computer_sn_cookie | | 5754 | AccessShareLock |
> testdb.computer_sn_cookie | | 5754 | RowExclusiveLock |
> testdb.computer_sn_cookie | | 5754 | AccessExclusiveLock |
> testdb.pg_attribute | | 5754 | AccessShareLock |
> testdb.sl_config_lock | | 5754 | AccessExclusiveLock |
> testdb.sl_trigger | | 5754 | AccessShareLock |
> testdb.csn_pk | | 5754 | AccessShareLock |
> testdb.pg_class | | 5754 | AccessShareLock |
> testdb.pg_class | | 5754 | RowShareLock |
> testdb.pg_class | | 5754 | RowExclusiveLock |
> testdb.address_type | | 5754 | AccessShareLock |
> testdb.address_type | | 5754 | RowExclusiveLock |
> testdb.address_type | | 5754 | AccessExclusiveLock |
> testdb.pg_namespace | | 5754 | AccessShareLock |
> testdb.pg_namespace | | 5754 | RowShareLock |
> testdb.csn_log_idx1 | | 5754 | RowExclusiveLock |
> testdb.computer_sn | | 5754 | AccessShareLock |
> testdb.computer_sn | | 5754 | RowExclusiveLock |
> testdb.computer_sn | | 5754 | AccessExclusiveLock |
> testdb.address_type | | 5987 | AccessShareLock | 5754
> | 9422 | 5987 | ExclusiveLock | 5754
> (55 rows)
>
> All responses will be welcomed.
>
> __
> Marc

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