Oracle in a Nutshell

System environment

The following views provide miscellaneous information about the current environment:

*$DB_PIPES

Provides information about database pipes currently defined in the database.

*$DBLINK

Provides information about all currently open database links.

*$FILESTAT

Provides information about the current read/write status of all datafiles.

*$FIXED_TABLE

Lists all *$ and X$ tables defined in the kernel.

*$FIXED_VIEW_DEFINITION

Provides a view definition for each dynamic performance view based upon the X$ tables.

*$GLOBAL_TRANSACTION

Provides information on all current global transactions.

*$INDEXED_FIXED_COLUMN

Lists each index column in the tables listed in *$FIXED_TABLE.

*$RESOURCE_LIMIT

Shows the current utilization of system resources that can be specified in the initialization file. Shoes the initial allocation, the current usage, and the maximum allowed value for each resource.

*$ROLLNAME

Lists the names of all rollback segments. Available after database is opened.

*$ROLLSTAT

Provides statistics about each rollback segment.

*$SYSSTAT

Provides the current values for each of the system statistics defined in *$STATNAME.

*$SYSTEM_CURSOR_CACHE

Provides information about cursor usage across all sessions.

*$SYSTEM_EVENT

Provides information about time spent waiting for each system event defined in *$EVENT_NAME.

*$TIMER

Provides access to a timer that increments every one-hundredth of a second.

*$TRANSACTION

Lists all active transactions in the system.

*$TRANSACTION_ENQUEUE

Lists all enqueues ...