7.111 V$BH

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

Column Datatype Description

FILE#

NUMBER

Data file identifier number (to find the file name, query DBA_DATA_FILES or V$DBFILE)

BLOCK#

NUMBER

Block number

CLASS#

NUMBER

Class number

STATUS

VARCHAR2(10)

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

  • pi - A past image in RAC mode

  • securefile - A secured file buffer

  • flashfree - A free flash cache buffer

  • flashcur - A current flash cache buffer

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This column is obsolete.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This column is obsolete.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This column is obsolete.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

CHAR(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Always set to N. This column is obsolete and maintained for backward compatibility.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.

CACHEHINT

NUMBER

Numeric representation of the values in the FLASH_CACHE and CELL_FLASH_CACHE columns. See the descriptions and possible values for the FLASH_CACHE and CELL_FLASH_CACHE columns in this view.

FLASH_CACHE

VARCHAR2(7)

Database Smart Flash Cache hint to be used for segment blocks:

  • DEFAULT

  • KEEP

  • NONE

Solaris and Oracle Linux functionality only.

CELL_FLASH_CACHE

VARCHAR2(7)

Cell flash cache hint to be used for segment blocks:

  • DEFAULT

  • KEEP

  • NONE

See Also: Oracle Exadata Storage Server Software documentation for more information

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data