Performance Views

V$RESOURCE_LIMIT Displays information about current and maximum global resource utilization for some system resources. Use this view to monitor the consumption of resources so that you can take corrective action, if necessary. Some resources, those used by DLM (Oracle Unix Distributed Lock Manager) for example, have an initial allocation (soft limit), and the hard limit, which is theoretically infinite (although in practice it is limited by SGA size). During SGA reservation/initialization, a place is reserved in SGA for the INITIAL_ALLOCATION of resources, but if this allocation is exceeded, additional resources are allocated up to the value indicated by LIMIT_VALUE. The CURRENT_UTILIZATION column indicates whether the initial allocation has been exceeded. When the initial allocation value is exceeded, the additional required resources are allocated from the shared pool, where they must compete for space with other resources. A good choice for the value of INITIAL_ALLOCATION will avoid the contention for space. For most resources, the value for INITIAL_ALLOCATION is the same as the LIMIT_VALUE. Exceeding LIMIT_VALUE results in an error. finish later Column Datatypes Description RESOURCE_NAME VARCHAR2(30) Name of the resource: dml_locks enqueue_locks enqueue_resources LM_PROCESSES Lock manager processes LM_LOCKS See local_listener max_shared_servers parallel_max_servers processes ROLLBACK_SEGMENTS See max_rollback_segments sessions SORT_SEGMENT_LOCKS value is computed by Oracle TEMPORARY_LOCKS value is computed by Oracle transactions CURRENT_UTILIZATION NUMBER Number of (resources, locks, or processes) currently being used. MAX_UTILIZATION NUMBER Maximum consumption of this resource since the last instance start-up. INITIAL_ALLOCATION VARCHAR2(10) Initial allocation. This will be equal to the value specified for the resource in the initialization parameter file (UNLIMITED for infinite allocation). LIMIT_VALUE VARCHAR2(10) Unlimited for resources and locks. This can be greater than the initial allocation value (UNLIMITED for infinite limit). Related Parameters: _enqueue_locks dml_locks Specifies the maximum number of DML locks--one for each table modified in a transaction. enqueue_resources Sets the number of resources that can be concurrently locked by the lock manager. Related Commands: ALTER TABLE DISABLE TABLE LOCK Related Views: V$ACCESS Displays objects in the database that are currently locked and the sessions that are accessing them. V$ENQUEUE_LOCK Displays all locks owned by enqueue state objects. V$ENQUEUE_STAT Contains detailed enqueue statistics for each enqueue. V$GLOBAL_BLOCKED_LOCKS Displays global blocked locks. V$LATCH Contains statistics for non-parent latches and summary statistics for parent latches. V$LOCK Lists the locks currently held by the Oracle database server and outstanding requests for a lock or latch. V$LOCKED_OBJECT Lists all locks acquired by every transaction on the system. V$PROCESS Contains information about the currently active processes. V$RESOURCE Contains resource name and address information V$SESS_IO Contains I/O statistics for each user session. V$SESSION Lists session information for each current session. V$SESSION_LONGOPS This view displays the status of various operations that run for longer than 6 seconds (in absolute time). V$SESSION_WAIT Lists the resources or events for which active sessions are waiting. V$SQLAREA Contains statistics about shared SQL area and contains one row for each SQL string. V$SYSSTAT >Contains session statistics Related Packages: DBMS_LOCK Lock Management services for your PL/SQL applications.