28.3. Viewing Locks

|     28.3. Viewing Locks     |                     |                                        |                  |                                |
|:---------------------------:|---------------------|----------------------------------------|------------------|--------------------------------|
|[Prev](monitoring-stats.html)|[Up](monitoring.html)|Chapter 28. Monitoring Database Activity|[Home](index.html)| [Next](progress-reporting.html)|

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## 28.3. Viewing Locks

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 Another useful tool for monitoring database activity is the `pg_locks` system table. It allows the database administrator to view information about the outstanding locks in the lock manager. For example, this capability can be used to:

* View all the locks currently outstanding, all the locks on relations in a particular database, all the locks on a particular relation, or all the locks held by a particular PostgreSQL session.

* Determine the relation in the current database with the most ungranted locks (which might be a source of contention among database clients).

* Determine the effect of lock contention on overall database performance, as well as the extent to which contention varies with overall database traffic.

 Details of the `pg_locks` view appear in [Section 52.74](view-pg-locks.html). For more information on locking and managing concurrency with PostgreSQL, refer to [Chapter 13](mvcc.html).

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