For almost every V$ view described in this chapter, Oracle has a corresponding GV$ (global V$) view. In Oracle Real Application Clusters, querying a GV$ view retrieves the V$ view information from all qualified instances. In addition to the V$ information, each GV$ view contains an extra column named INST_ID of data type NUMBER. The INST_ID column displays the instance number from which the associated V$ view information was obtained. The INST_ID column can be used as a filter to retrieve V$ information from a subset of available instances. For example, the following query retrieves the information from the V$LOCK view on instances 2 and 5:
SQL> SELECT * FROM GV$LOCK WHERE INST_ID = 2 OR INST_ID = 5;
See Also:
Oracle Real Application Clusters Installation and Configuration Guide for your operating system
GV$ views are CONTAINER_DATA objects. When a user connected to the root queries a GV$ view, the query results will depend on the CONTAINER_DATA attribute for users for the view. The CONTAINER_DATA clause of the SQL ALTER USER statement is used to set and modify users' CONTAINER_DATA attribute.
See Also:
Oracle Database Security Guide for more information about container data objects
Oracle Database SQL Language Reference for more information about the CONTAINER_DATA clause for the SQL ALTER USER statement