8.113 V$BUFFER_POOL

V$BUFFER_POOL displays information about all buffer pools available for the instance.

Column Datatype Description

ID

NUMBER

Buffer pool identifier number

NAME

VARCHAR2(20)

Name of the buffer pool:

  • DEFAULT

  • KEEP

  • RECYCLE

    Note: Currently, KEEP and RECYCLE pools only exist for the standard block size. All nonstandard block size pools are DEFAULT.

BLOCK_SIZE

NUMBER

Block size (in bytes) for buffers in this pool. Possible values: the standard block size, the power of 2 nonstandard block sizes, 2048, 4096, 8192, 16384, 32768.

RESIZE_STATE

VARCHAR2(10)

Current state of the resize operation:

STATIC - Not being resized

ALLOCATING - Memory is being allocated (can be canceled by the user)

ACTIVATING - New buffers are being created (user cannot cancel)

SHRINKING - Buffers are being deleted (can be canceled by the user)

CURRENT_SIZE

NUMBER

Present size of the sub-cache (in megabytes)

BUFFERS

NUMBER

Current instantaneous number of buffers

TARGET_SIZE

NUMBER

If a resize is in progress (state is not STATIC), records new target size (in megabytes). If the pool is STATIC, the value in this column is the same as the current size of the pool.

TARGET_BUFFERS

NUMBER

If a resize is in progress, records new target size in terms of buffers. Otherwise, the value in this column is the same as the current number of buffers.

PREV_SIZE

NUMBER

Previous buffer pool size. If the buffer pool has never been resized, the previous size is zero.

PREV_BUFFERS

NUMBER

Previous number of buffers in the buffer pool. Value is zero if the buffer pool has never been resized.

LO_BNUM

NUMBER

Obsolete column

HI_BNUM

NUMBER

Obsolete column

LO_SETID

NUMBER

Obsolete column

HI_SETID

NUMBER

Obsolete column

SET_COUNT

NUMBER

Obsolete column

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

See Also:

"DB_BLOCK_SIZE"