Blog dedicated to Oracle Applications (E-Business Suite) Technology; covers Apps Architecture, Administration and third party bolt-ons to Apps

Thursday, June 18, 2009

Oracle's v$ views

Vinu asked me whether we can insert a new directory for utl_file_dir into v$parameter. I explained to him that v$views are not tables and are synonyms of v_$ dynamic performance views. These views are available even before database is in OPEN state. Although these views appear to be regular database tables, they are not. These views provide data on internal disk structures and memory structures. These views can be selected from, but never updated or altered by the user.

The file $ORACLE_HOME/rdbms/admin/catalog.sql contains definitions of the views and public synonyms for the dynamic performance views.

Once the instance is started, the V_$ views that read from memory are accessible. Views that read data from disk require that the database be mounted.

You can find the description of the v$ synonyms here.

No comments: