Oracle 11g R2性能优化 tkprof

另一篇博文总结了关于SQL TRACE工具的使用方式，但是产生的trace文件格式阅读起来并不是十分友好，为了更好的分析trace文件，Oracle也自带了一个格式化工具tkprof。tkprof工具用于处理原始的trace文件，合并汇总trace文件当中一些项目值，然后进行格式化，这样就使得trace文件的可读性更好。

关于tkprof的详细说明可以参考官方文档：Understanding SQL Trace and TKPROF

关于trace文件的生成可以参考另一篇博文：Oracle 11g R2性能优化 SQL TRACE

主要说明

tkprof命令位于 $ORACLE_HOME/bin/路径下，通过命令tkprof直接获取相关选项参数：

$ tkprof

Usage: tkprof tracefile outputfile [explain= ] [table= ]

[print= ] [insert= ] [sys= ] [sort= ]

关键选项

tracefile

需要格式化的trace文件
outputfile

格式化完成后的输出文件
explain=

通过给定方式连接数据库，并为每条语句生成执行计划
sort=

指定排序键来展示SQL语句

其他选项如下：



  table=schema.tablename   Use 'schema.tablename' with 'explain=' option. -- 指定PLAN_TABLE生成执行计划，默认为系统的PLAN_TABLE

  explain=user/password    Connect to ORACLE and issue EXPLAIN PLAN.

  print=integer    List only the first 'integer' SQL statements. -- 显示指定数目的SQL语句

  aggregate=yes|no -- 指定是否对重复SQL语句信息合并，默认yes合并，如果指定为no，对重复SQL语句信息会独立输出一个条目

  insert=filename  List SQL statements and data inside INSERT statements. -- 创建一张表将每个跟踪的SQL语句的一行统计信息插入到表中

  sys=no           TKPROF does not list SQL statements run as user SYS. -- 指定不记录由SYS用户执行的语句

  record=filename  Record non-recursive statements found in the trace file. -- 指定生成不包含递归语句的SQL语句文件

  waits=yes|no     Record summary for any wait events found in the trace file. -- 指定为语句生成等待事件信息(如有)

-- 以下为排序选项说明

  sort=option      Set of zero or more of the following sort options:

-- 1、解析调用期间执行排序

    prscnt  number of times parse was called                     -- 解析次数

    prscpu  cpu time parsing                                     -- 解析消耗CPU时间

    prsela  elapsed time parsing                                 -- 解析所消耗时间

    prsdsk  number of disk reads during parse                    -- 解析时物理读次数

    prsqry  number of buffers for consistent read during parse   -- 解析时一致读次数

    prscu   number of buffers for current read during parse      -- 解析时当前读次数

    prsmis  number of misses in library cache during parse       -- 解析时库缓存区未命中次数

-- 2、执行调用期间执行排序

    execnt  number of execute was called                         -- 执行次数

    execpu  cpu time spent executing                             -- 执行时消耗CPU时间

    exeela  elapsed time executing                               -- 执行所消耗的时间

    exedsk  number of disk reads during execute                  -- 执行时物理读次数

    exeqry  number of buffers for consistent read during execute -- 执行时一致读次数

    execu   number of buffers for current read during execute    -- 执行时当前读次数

    exerow  number of rows processed during execute              -- 执行时处理的记录数

    exemis  number of library cache misses during execute        -- 执行时库缓冲区未命中次数

-- 3、提取调用期间执行排序

    fchcnt  number of times fetch was called                     -- 提取数据次数

    fchcpu  cpu time spent fetching                              -- 提取时消耗CPU时间

    fchela  elapsed time fetching                                -- 提取所消耗的时间

    fchdsk  number of disk reads during fetch                    -- 提取时物理读次数

    fchqry  number of buffers for consistent read during fetch   -- 提取时一致读次数

    fchcu   number of buffers for current read during fetch      -- 提取时当前读次数

    fchrow  number of rows fetched                               -- 提取的记录数

    userid  userid of user that parsed the cursor                -- 按游标解析时的userid排序

关于tkprof工具更详细的用法可以参考Oracle MOS文档：TKProf Interpretation (9i and above) (文档 ID 760786.1)

用法示例

对SCOTT开启跟踪

$ sqlplus scott/tiger

SCOTT@dbabd> alter session set tracefile_identifier = 'SCOTT';

Session altered.

SCOTT@dbabd> exec dbms_session.session_trace_enable(true, true, 'all_executions');

PL/SQL procedure successfully completed.

执行一条SQL语句

SCOTT@dbabd> select * from emp;

     EMPNO ENAME      JOB                    MGR HIREDATE                   SAL       COMM     DEPTNO

---------- ---------- --------------- ---------- ------------------- ---------- ---------- ----------

      7369 SMITH      CLERK                 7902 1980-12-17 00:00:00        800                    20

      7499 ALLEN      SALESMAN              7698 1981-02-20 00:00:00       1600        300         30

      7521 WARD       SALESMAN              7698 1981-02-22 00:00:00       1250        500         30

      7566 JONES      MANAGER               7839 1981-04-02 00:00:00       2975                    20

      7654 MARTIN     SALESMAN              7698 1981-09-28 00:00:00       1250       1400         30

      7698 BLAKE      MANAGER               7839 1981-05-01 00:00:00       2850                    30

      7782 CLARK      MANAGER               7839 1981-06-09 00:00:00       2450                    10

      7788 SCOTT      ANALYST               7566 1987-04-19 00:00:00       3000                    20

      7839 KING       PRESIDENT                  1981-11-17 00:00:00       5000                    10

      7844 TURNER     SALESMAN              7698 1981-09-08 00:00:00       1500          0         30

      7876 ADAMS      CLERK                 7788 1987-05-23 00:00:00       1100                    20

      7900 JAMES      CLERK                 7698 1981-12-03 00:00:00        950                    30

      7902 FORD       ANALYST               7566 1981-12-03 00:00:00       3000                    20

      7934 MILLER     CLERK                 7782 1982-01-23 00:00:00       1300                    10

14 rows selected.

对SCOTT关闭跟踪

SCOTT@dbabd> exec dbms_session.session_trace_disable();

PL/SQL procedure successfully completed.

tkprof分析trace文件

执行如下命令生成格式化文件：

$ tkprof /data/app/oracle/diag/rdbms/dbabd/dbabd/trace/dbabd_ora_18629_SCOTT.trc /data/app/scott_trace.log explain=scott/tiger aggregate=yes sys=no waits=yes sort=fchela

查看tkprof生成文件：

$ cat /data/app/scott_trace.log

-- 开头概要部分，基本信息说明，包括tkprof版本、trace文件路径、排序选项和报告参数说明

TKPROF: Release 11.2.0.4.0 - Development on Thu Jan 17 17:41:04 2019

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

Trace file: /data/app/oracle/diag/rdbms/dbabd/dbabd/trace/dbabd_ora_18629_SCOTT.trc

Sort options: fchela

********************************************************************************

count    = number of times OCI procedure was executed

cpu      = cpu time in seconds executing

elapsed  = elapsed time in seconds executing

disk     = number of physical reads of buffers from disk

query    = number of buffers gotten for consistent read

current  = number of buffers gotten in current mode (usually for update)

rows     = number of rows processed by the fetch or execute call

********************************************************************************

-- 跟踪的SQL语句文本、SQL ID和执行计划HASH

SQL ID: a2dk8bdn0ujx7 Plan Hash: 3956160932

select *

from

 emp

-- SQL执行的统计信息

/*

call:调用类型

count:调用执行次数

cpu:需要的CPU时间(单位:秒)

elapsed:需要消耗的时间(单位:秒)

disk:发生物理读次数

query:发生一致读次数

current:发生当前读次数

rows:获取的行数

*/

call     count       cpu    elapsed       disk      query    current        rows

------- ------  -------- ---------- ---------- ---------- ----------  ----------

Parse        1      0.00       0.00          0          0          0           0

Execute      1      0.00       0.00          0          0          0           0

Fetch        2      0.00       0.00          0          7          0          14

------- ------  -------- ---------- ---------- ---------- ----------  ----------

total        4      0.00       0.00          0          7          0          14

Misses in library cache during parse: 1     -- 库缓存没有命中数，说明是硬解析

Optimizer mode: ALL_ROWS                    -- 优化器模式

Parsing user id: 83  (SCOTT)                -- 解析用户

Number of plan statistics captured: 1       -- 执行计划统计信息获取数

-- SQL语句实际执行消耗的资源信息

/*

Rows:操作实际返回记录数

Row Source Operation:当前行操作的访问方式

    cr:一致性读的数据块，对应query的Fetch值

    pr:物理读的数据块，对应disk的Fetch值

    pw:物理写的数据块

    time:执行时间

    cost:优化器执行成本

    size:处理的字节数

    card:处理的记录数

*/

Rows (1st) Rows (avg) Rows (max)  Row Source Operation

---------- ---------- ----------  ---------------------------------------------------

        14         14         14  TABLE ACCESS FULL EMP (cr=7 pr=0 pw=0 time=211 us cost=3 size=532 card=14)

-- 指定explain选项输出的执行计划

Rows     Execution Plan

-------  ---------------------------------------------------

      0  SELECT STATEMENT   MODE: ALL_ROWS

     14   TABLE ACCESS   MODE: ANALYZED (FULL) OF 'EMP' (TABLE)

-- 指定选项waits=yes选项输出的等待事件信息统计

Elapsed times include waiting on following events:

  Event waited on                             Times   Max. Wait  Total Waited

  ----------------------------------------   Waited  ----------  ------------

  SQL*Net message to client                       2        0.00          0.00

  SQL*Net message from client                     2      128.00        128.00

********************************************************************************

SQL ID: bnqn0qyvy59qf Plan Hash: 0

BEGIN dbms_session.session_trace_enable(true, true, 'all_executions'); END;

call     count       cpu    elapsed       disk      query    current        rows

------- ------  -------- ---------- ---------- ---------- ----------  ----------

Parse        0      0.00       0.00          0          0          0           0

Execute      1      0.00       0.00          0         61          0           1

Fetch        0      0.00       0.00          0          0          0           0

------- ------  -------- ---------- ---------- ---------- ----------  ----------

total        1      0.00       0.00          0         61          0           1

Misses in library cache during parse: 0

Misses in library cache during execute: 1

Optimizer mode: ALL_ROWS

Parsing user id: 83  (SCOTT)

Elapsed times include waiting on following events:

  Event waited on                             Times   Max. Wait  Total Waited

  ----------------------------------------   Waited  ----------  ------------

  SQL*Net message to client                       1        0.00          0.00

  SQL*Net message from client                     1       68.47         68.47

********************************************************************************

SQL ID: 23d3sap7cask4 Plan Hash: 0

BEGIN dbms_session.session_trace_disable(); END;

call     count       cpu    elapsed       disk      query    current        rows

------- ------  -------- ---------- ---------- ---------- ----------  ----------

Parse        1      0.00       0.00          0          0          0           0

Execute      1      0.00       0.00          0          0          0           1

Fetch        0      0.00       0.00          0          0          0           0

------- ------  -------- ---------- ---------- ---------- ----------  ----------

total        2      0.00       0.00          0          0          0           1

Misses in library cache during parse: 1

Optimizer mode: ALL_ROWS

Parsing user id: 83  (SCOTT)

********************************************************************************

-- 开启跟踪期间所有非递归SQL语句执行信息统计汇总

OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS

call     count       cpu    elapsed       disk      query    current        rows

------- ------  -------- ---------- ---------- ---------- ----------  ----------

Parse        2      0.01       0.01          0          0          0           0

Execute      3      0.00       0.00          0         61          0           2

Fetch        2      0.00       0.00          0          7          0          14

------- ------  -------- ---------- ---------- ---------- ----------  ----------

total        7      0.01       0.01          0         68          0          16

Misses in library cache during parse: 2

Misses in library cache during execute: 1

Elapsed times include waiting on following events:

  Event waited on                             Times   Max. Wait  Total Waited

  ----------------------------------------   Waited  ----------  ------------

  SQL*Net message to client                       3        0.00          0.00

  SQL*Net message from client                     3      128.00        196.48

-- 开启跟踪期间所有递归SQL语句执行信息统计汇总

OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS

call     count       cpu    elapsed       disk      query    current        rows

------- ------  -------- ---------- ---------- ---------- ----------  ----------

Parse        0      0.00       0.00          0          0          0           0

Execute     23      0.00       0.00          0          0          0           0

Fetch       37      0.00       0.00          2         82          0          28

------- ------  -------- ---------- ---------- ---------- ----------  ----------

total       60      0.00       0.00          2         82          0          28

Misses in library cache during parse: 0

Elapsed times include waiting on following events:

  Event waited on                             Times   Max. Wait  Total Waited

  ----------------------------------------   Waited  ----------  ------------

  db file sequential read                         2        0.00          0.00

-- 所有分析的SQL语句汇总统计

    3  user  SQL statements in session.

   13  internal SQL statements in session.

   16  SQL statements in session.

    1  statement EXPLAINed in this session.

********************************************************************************

Trace file: /data/app/oracle/diag/rdbms/dbabd/dbabd/trace/dbabd_ora_18629_SCOTT.trc

Trace file compatibility: 11.1.0.7

Sort options: fchela

       1  session in tracefile.

       3  user  SQL statements in trace file.

      13  internal SQL statements in trace file.

      16  SQL statements in trace file.

      16  unique SQL statements in trace file.

       1  SQL statements EXPLAINed using schema:

           SCOTT.prof$plan_table

             Default table was used.

             Table was created.

             Table was dropped.

     411  lines in trace file.

     196  elapsed seconds in trace file.

总结

以上梳理了关于tkprof工具的简单用法，经过它格式化之后的trace文件更具有可读性，真实地统计了SQL语句在执行过程当中资源的消耗。但是它提供的是汇总后的统计信息，如果需要了解SQL语句执行时每个步骤的资源消耗情况可以通过阅读原始的trace文件，这里不再进行深入讨论了。SQL性能优化博大精深，涉及的知识面广泛，也经常涉及Oracle底层运行机制和操作系统底层实现，需要自己学习与提高的地方还有很多。

参考

https://docs.oracle.com/cd/E11882_01/server.112/e41573/sqltrace.htm#PFGRF94981

TKProf Interpretation (9i and above) (文档 ID 760786.1)

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