Skip Headers
Oracle® Database Reference
10g Release 2 (10.2)

Part Number B14237-01
Go to Documentation Home
Home
Go to Book List
Book List
Go to Table of Contents
Contents
Go to Index
Index
Go to Master Index
Master Index
Go to Feedback page
Feedback

Go to previous page
Previous
Go to next page
Next
View PDF

V$CACHE_LOCK

This is a 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.

Column Datatype Description
FILE# NUMBER Datafile identifier number (to find filename, query DBA_DATA_FILES or V$DBFILE)
BLOCK# NUMBER Block number
STATUS VARCHAR2(6) Status of the 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 | 8) 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 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 reread from the cache because another instance has forced it out of this instance's cache by requesting the lock on the block in exclusive mode
FORCED_WRITES NUMBER Number of times GCS had to write this block to cache because this instance had used the block and another instance had requested the lock on the block in a conflicting mode
INDX NUMBER Platform-specific lock manager identifier
CLASS NUMBER Platform-specific lock manager identifier