Обсуждение: lock help

I have a db wedged and need help dealing with it.  How can I
find out more about this, who, what, where, etc, and how
to free this up:

ghiza=# select * from pg_user;
 usename | usesysid | usecreatedb | usesuper | usecatupd |  passwd  | valuntil | useconfig
---------+----------+-------------+----------+-----------+----------+----------+-----------
 pgadmin |       10 | t           | t        | t         | ******** |          |
 ghiza   |    16385 | f           | f        | f         | ******** |          |
(2 rows)

ghiza=# select version();
                                              version
---------------------------------------------------------------------------------------------------
 PostgreSQL 8.2.6 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.4.6 20060404 (Red Hat 3.4.6-9)
(1 row)

Ray Stell <stellr@cns.vt.edu> writes:
> I have a db wedged and need help dealing with it.

Define "wedged" --- what's the actual problem?

If it is a locking issue then the pg_locks view might be useful.

            regards, tom lane

On Thu, Mar 20, 2008 at 10:42:29AM -0400, Tom Lane wrote:
> Ray Stell <stellr@cns.vt.edu> writes:
> Define "wedged" --- what's the actual problem?

client queries not returning.


> If it is a locking issue then the pg_locks view might be useful.

duh, I meant to cut and paste the lock info and sent user info
by being in a panic.

ghiza=# select * from pg_locks;
   locktype    | database | relation | page | tuple | transactionid | classid | objid | objsubid | transaction |  pid
|     mode       | granted  

---------------+----------+----------+------+-------+---------------+---------+-------+----------+-------------+-------+-----------------+---------
 relation      |    16384 |    10328 |      |       |               |         |       |          |    15470960 | 30765
|AccessShareLock | t 
 transactionid |          |          |      |       |      15470960 |         |       |          |    15470960 | 30765
|ExclusiveLock   | t 
(2 rows)

As it turns out this app is distributed across 3 or 4 dbs and it was an oracle
instance that was hung.  However, I was ill prepared to eval the state of
the pg db.  Is there a good place to focus in the docs on how to evaluate
locking issues.

Thanks.