Wednesday, August 20, 2008

V$SQL_PLAN_STATISTICS

Oracle 11gR1

V$SQL_PLAN_STATISTICS provides execution statistics at the row source level for each child cursor.

Column

Datatype

Description

ADDRESS

RAW(4 | 8)

Address of the handle to the parent for this cursor

HASH_VALUE

NUMBER

Hash value of the parent statement in the library cache. The two columns ADDRESS and HASH_VALUE can be used to join with V$SQLAREA to locate the parent cursor.

SQL_ID

VARCHAR2(13)

SQL identifier of the parent statement in the library cache

PLAN_HASH_VALUE

NUMBER

Numerical representation of the SQL plan for this cursor. Comparing one PLAN_HASH_VALUE to another easily identifies whether or not two plans are the same (rather than comparing the two plans line by line)

CHILD_NUMBER

NUMBER

Number of the child cursor that uses this work area. The columns ADDRESS, HASH_VALUE, and CHILD_NUMBER can be used to join with V$SQL to locate the child cursor using this area.

OPERATION_ID

NUMBER

A number assigned to each step in the execution plan

EXECUTIONS

NUMBER

Number of times this cursor has been executed

LAST_STARTS

NUMBER

Number of times this operation has been started, during the last execution

STARTS

NUMBER

Number of times this operation has been started, accumulated over the past executions

LAST_OUTPUT_ROWS

NUMBER

Number of rows produced by the row source, during the last execution

OUTPUT_ROWS

NUMBER

Number of rows produced by the row source, accumulated over the past executions

LAST_CR_BUFFER_GETS

NUMBER

Number of buffers retrieved in consistent mode, during the last execution. Buffers are usually retrieved in consistent mode for queries.

CR_BUFFER_GETS

NUMBER

Number of buffers retrieved in consistent mode, accumulated over the past executions. Buffers are usually retrieved in consistent mode for queries.

LAST_CU_BUFFER_GETS

NUMBER

Number of buffers retrieved in current mode, during the last execution. Buffers are retrieved in current mode for statements such as INSERT, UPDATE, and DELETE.

CU_BUFFER_GETS

NUMBER

Number of buffers retrieved in current mode, accumulated over the past executions. Buffers are retrieved in current mode for statements such as INSERT, UPDATE, and DELETE.

LAST_DISK_READS

NUMBER

Number of physical disk reads performed by the operation, during the last execution

DISK_READS

NUMBER

Number of physical disk reads performed by the operation, accumulated over the past executions

LAST_DISK_WRITES

NUMBER

Number of physical disk writes performed by the operation, during the last execution

DISK_WRITES

NUMBER

Number of physical disk writes performed by the operation, accumulated over the past executions

LAST_ELAPSED_TIME

NUMBER

Elapsed time (in microseconds) corresponding to this operation, during the last execution

ELAPSED_TIME

NUMBER

Elapsed time (in microseconds) corresponding to this operation, accumulated over the past executions

Note:

Oracle dynamic performance views

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