V$BH

V$BH displays the status and number of pings for every buffer in the SGA. This is a Real Application Clusters view.

Column Datatype Description
FILE# NUMBER Datafile identifier number (to find the filename, query DBA_DATA_FILES or V$DBFILE)
BLOCK# NUMBER Block number
CLASS# NUMBER Class number
STATUS VARCHAR2(6) Status of the buffer:

  • 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XNC NUMBER This column is obsolete. Its value is hard-coded to 0.
FORCED_READS NUMBER This column is obsolete. Its value is hard-coded to 0.
FORCED_WRITES NUMBER This column is obsolete. Its value is hard-coded to 0.
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 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_CLASS 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.
DIRTY VARCHAR2(1) Y - block modified
TEMP VARCHAR2(1) Y - temporary block
PING VARCHAR2(1) Y - block pinged
STALE VARCHAR2(1) Y - block is stale
DIRECT VARCHAR2(1) Y - direct block
NEW VARCHAR2(1) Always set to N. This column is obsolete and maintained for backward compatibility.
OBJD NUMBER Database object number of the block that the buffer represents
TS# NUMBER Tablespace number of block
LOBID NUMBER If the buffer belongs to a SecureFiles object, the value in this column is the unique identifier for the SecureFiles object. For other buffer types, the value in this column is meaningless.