Dynamic Performance (V$) Views, 26 of 237

V$CACHE_LOCK

This is an Oracle9i Real Application Clusters view. V$CACHE_LOCK is similar to V$CACHE, except for the platform specific lock manager identifiers. This information may be useful if the platform- specific lock manager provides tools for monitoring the PCM lock operations that are occurring. For example, first query to find the lock element address using INDX and CLASS, then query V$BH to find the buffers that are covered by the lock.

See Also:

Column	Datatype	Description
`FILE#`	`NUMBER`	Datafile identifier number (to find filename, query `DBA_DATA_FILES` or `V$DBFILES`)
`BLOCK#`	`NUMBER`	Block number
`STATUS`	`VARCHAR2(4)`	Status of block: `FREE` - not currently in use `XCUR` - exclusive `SCUR` - shared current `CR` - consistent read `READ` - being read from disk `MREC` - in media recovery mode `IREC` - in instance recovery mode
`XNC`	`NUMBER`	Number of parallel cache management (PCM) lock conversions due to contention with another instance
`NAME`	`VARCHAR2(30)`	Name of the database object containing the block
`KIND`	`VARCHAR2(12)`	Type of database object:
		`1`: index `2:` table `3`: cluster `4`: view `5`: synonym `6`: sequence `7`: procedure `8`: function `9`: package `10`: nonexistent	`11`: package body `12`: trigger `13`: type `14`: type body `19`: table partition `20`: index partition `21`: LOB `22`: library `Null`: Unknown
`OWNER#`	`NUMBER`	Owner number
`LOCK_ELEMENT_ADDR`	`RAW(4)`	The address of the lock element that contains the PCM lock that is covering the buffer. If more than one buffer has the same address, then these buffers are covered by the same PCM lock.
`LOCK_ELEMENT_NAME`	`NUMBER`	The address of the lock element that contains the PCM lock that is covering the buffer. If more than one buffer has the same address, then these buffers are covered by the same PCM lock.
`FORCED_READS`	`NUMBER`	Number of times the block had to be made re-read from disk because another instance had forced it out of this instance's cache by requesting the PCM lock on this block in lock mode
`FORCED_WRITES`	`NUMBER`	Number of times DBWR had to write this block to disk because this instance had dirtied the block and another instance had requested the PCM lock on the block in conflicting mode.
`INDX`	`NUMBER`	Platform-specific lock manager identifier
`CLASS`	`NUMBER`	Platform-specific lock manager identifier