Some important VIEWS that we frequently query in Oracle database as a DBA.
When DBA_.. then Datadictionary Table and V$..then it is Datadictionary View.
DATABASE_PROPERTIES - List most of the mejor properties of any database
DBA_TABLESPACES - Complete information about tablespaces.
DBA_DATA_FILES - Complete information of the files present in the Tablespaces.
DBA_TEMP_FILES - File's information of temporary tablespace.
DBA_EXTENTS - To check the extents for a given segment.
DBA_SEGMENTS - View to get number of extents and blocks allocated to a Segment.
DBA_FREE_SPACE - Displays free extents in tablespace.
DBA_TABLES - All the information about tables can be obtained here.
DBA_OBJECTS - All the information about objects in table can be Obtained here.
DBA_INDEXES - Provides information about the indexes.
DBA_IND_COLUMNS - Provides information about the indexed columns.
V$OBJECT_USAGE - Provides information on the usage of Indexes and Tables.
DBA_CONSTRAINTS - To obtain name, type and status of all constraints.
DBA_CONS_COLUMNS- To obtain the columns in the constraints on table.
DBA_USERS - To obtain information about account status, default Tablespace for users.
DBA_PROPERTIES - View to display passwd profile information.
DBA_TS_QUOTAS - Amount of space a user can use in tablespaces.
DBA_SYS_PRIVS - Lists system privileges granted to users and roles.
V$SESSION_PRIVS - Lists the privileges that are currently available to user.
DBA_TAB_PRIVS - Lists all grants and owners of all Tables in the database.
DBA_COL_PRIVS - Lists all grants and owners of all columns in the database.
DBA_ROLES - All roles that exist in the database.
DBA_ROLES_PRIVS - Roles granted to users and roles.
DBA_SYS_PRIVS - System privileges granted to users and roles.
DBA_UNUSED_COL_TABS - To identify tables with unused columns.
DBA_PARTIAL_DROP_TABS - To identify tables that have partially Completed DROP columns operations.
DBA_ROLLBACK_SEGS - To obtain information about all the undo segments In the database.
Information about undo segments that are offline can be seen only in this view.
V$CONTROLFILE - Lists the names and status of the control files.
V$DATABASE - Contains database information from the control files.
V$VERSION - Version numbers of core library components in oracle server.
V$INSTANCE - Displays the state of the current instance.
V$DATAFILE - Contains data file information from control file.
V$TABLESPACE - Displays tablespace information from the control file.
V$LOGFILE - Displays each redo log group, member and status of each Member.
V$LOG - Same as above.
V$THREAD - To display the current redo log group, the number of online redo log groups and current sequence number.
V$PARAMETER - Lists parameters and values currently in effect for the Session also status and location of all parameters.
V$SESSION - Lists session information for each current session.
V$SPPARAMETER - Lists the contents of SPFILE.
V$SGA - Contains summary information on SGA.
V$FIXED_TABLE - To find list of data dictionary views.
V$ROLLSTAT - Views to obtain the statistics of the undo Segments currently used by the instance.
V$ROLLNAME - same as above
V$ROLE_SYS_PRIVS - System privileges granted to roles.
V$ROLE_TAB_PRIVS - Object privileges granted to roles.
V$SESSION_ROLES - Roles that the user currently has enabled.
V$ROLE_ROL_PRIVS - Roles that are granted to roles.
