Dynamic Performance (V$) Views, 24 of 179

V$CACHE_LOCK

This is an Oracle Parallel Server 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$BH to find the buffers that are covered by the lock. See also "V$CACHE".

See Also:
Oracle8i Parallel Server Concepts.

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

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