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Oracle 视图 V$OPTIMIZER_PROCESSING_RATE 官方解释，作用，如何使用详细说明

本站中文解释

Oracle视图V$OPTIMIZER_PROCESSING_RATE查看在搜索优化计划框架期间搜索优化器正在执行的优化进程的处理速率。该视图报告每秒处理进程(processes/sec)，每秒优化运算符(operators/sec)，每秒去除重复优化运算符(distinct operators/sec)，以及每秒搜索空间节点(searches/sec)。

EXPLAIN PLAN语句可以用来使用V$OPTIMIZER_PROCESSING_RATE视图，以查看优化的速率。首先，需要在会话中启用搜索优化计划框架：

ALTER SESSION SET optimizer_use_pending_statistics = true;

随后，可以执行EXPLAIN PLAN来开始搜索优化过程：

EXPLAIN PLAN FOR SELECT * FROM emp;

最后，可以查询V$OPTIMIZER_PROCESSING_RATE视图并获得计算对最新EXPLAIN PLAN语句运行优化操作的速率：

SELECT process_rate, operators_rate, distinct_operators_rate, searches_rate FROM v$optimizer_processing_rate;

官方英文解释

V$OPTIMIZER_PROCESSING_RATE displays the processing rates used by the optimizer to compute degree of parallelism.

Note:

You can manipulate these rates using these procedures for the DBMS_STATS package:

  • SET_PROCESSING_RATE

  • DELETE_PROCESSING_RATE

  • GATHER_PROCESSING_RATE

See Oracle Database PL/SQL
Packages and Types Reference for more information about the DBMS_STATS package.

Column Datatype Description

ADDRESS

RAW(4| 8)

Address of the handle to the parent for this cursor

OPERATION_NAME

VARCHAR2(64)

Name of the operation. The possible values are AGGR, ALL, CPU, CPU_ACCESS, CPU_AGGR, CPU_BYTES_PER_SEC, CPU_FILTER, CPU_GBY, CPU_HASH_JOIN, CPU_JOIN, CPU_NL_JOIN, CPU_RANDOM_ACCESS, CPU_ROWS_PER_SEC, CPU_SEQUENTIAL_ACCESS, CPU_SM_JOIN, CPU_SORT, HASH, IO, IO_ACCESS, IO_BYTES_PER_SEC, IO_RANDOM_ACCESS, IO_ROWS_PER_SEC, IO_SEQUENTIAL_ACCESS, MEMCMP, MEMCPY

MANUAL_VALUE

VARCHAR2(10)

Value of the operation set manually by the user

CALIBRATION_VALUE

VARCHAR2(10)

Value of the operation obtained from calibration (by running the GATHER_PROCESSING_RATE procedure)

DEFAULT_VALUE

VARCHAR2(10)

Default value of the operation

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


数据运维技术 » Oracle 视图 V$OPTIMIZER_PROCESSING_RATE 官方解释，作用，如何使用详细说明
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