# 27.3. Viewing Locks 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 51.74](https://www.postgresql.org/docs/12/view-pg-locks.html). For more information on locking and managing concurrency with PostgreSQL, refer to [Chapter 13](https://www.postgresql.org/docs/12/mvcc.html). --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.postgresql.tw/13/server-administration/monitoring-database-activity/viewing-locks.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.