Oracle in a Nutshell

Oracle Parallel Server/Real Application Clusters

The following views are specific to an Oracle Parallel Server/Real Application Clusters environment:

*$ACTIVE_INSTANCES

Lists all current instances that have the database mounted.

*$BH

Provides the status and pings of every data buffer in the System Global Area (SGA). Available after database is opened.

*$CACHE

Provides information about the block header of every object the current instance has in its SGA. Available after database is opened.

*$CACHE_LOCK

Provides the lock status of every data block the current instance has in its SGA. Available after database is opened.

*$CLASS_PING

Shows statistics on the number of pings per data block class.

*$FALSE_PING

Lists buffers that are getting excessive pings because they are covered under a different lock. Buffers that are identified can be remapped using the initialization parameter GC_FILES_TO_LOCKS. Available after database is opened.

*$ENQUEUE_STAT

Lists statistics about each of the different types of enqueue request for a particular database instance. An enqueue is used to prevent multiple users or processes from writing to the same data block at the same time. New with Oracle9i.

*$FILES_CACHE_TRANSFER

Shows the number of block pings per datafile. Prior to Oracle9i this view was called *$FILE_PING. Available after database is mounted.

*$GCSHVMASTER

Tracks the mastering of Global Cache Service resources, except those that are in files that are mapped to a specific instance. New with Oracle9 ...