Oracle数据库中使用DBMS_PROFILER进行调优

5/7/2008来源:Oracle教程人气:4524

在进行数据库调优时,代码的性能瓶颈至关重要,Oracle数据库提供的DBMS_PROFILER包可以特别方便的发现瓶颈的所在之处。

DBMS_PROFILER在使用之前可能需要安装,具体安装步骤如下:

◆1:执行$ORACLE_HOME/rdbms/admin/profload.sql

◆2:创建一个用于存放跟踪信息的schema

CREATE USER profiler IDENTIFIED BY profiler DEFAULT TABLESPACE users QUOTA UNLIMITED ON users;

GRANT connect TO profiler;

CREATE PUBLIC SYNONYM plsql_profiler_runs FOR profiler.plsql_profiler_runs;

CREATE PUBLIC SYNONYM plsql_profiler_units FOR profiler.plsql_profiler_units;

CREATE PUBLIC SYNONYM plsql_profiler_data FOR profiler.plsql_profiler_data;

CREATE PUBLIC SYNONYM plsql_profiler_runnumber FOR profiler.plsql_profiler_runnumber;

◆3:使用刚刚创建的profiler用户执行如下脚本或代码:

$ORACLE_HOME/rdbms/admin/proftab.sql

GRANT SELECT ON plsql_profiler_runnumber TO PUBLIC;

GRANT SELECT, INSERT, UPDATE, DELETE ON plsql_profiler_data TO PUBLIC;

GRANT SELECT, INSERT, UPDATE, DELETE ON plsql_profiler_units TO PUBLIC;

GRANT SELECT, INSERT, UPDATE, DELETE ON plsql_profiler_runs TO PUBLIC;

安装成功后测试:

执行

BEGIN

DBMS_PROFILER.START_PROFILER('123');

FOR I IN 1 .. 1000 LOOP

INSERT INTO A VALUES (I || '');

END LOOP;

COMMIT;

DBMS_PROFILER.STOP_PROFILER();

END;

执行后使用下面的代码检查:

SELECT C.LINE#, C.TOTAL_OCCUR, C.TOTAL_TIME, C.MIN_TIME, C.MAX_TIME

FROM PLSQL_PROFILER_RUNS A, PLSQL_PROFILER_UNITS B, PLSQL_PROFILER_DATA C

WHERE A.RUN_COMMENT = '123'

AND B.UNIT_OWNER = ''

AND A.RUNID = B.RUNID

AND A.RUNID = C.RUNID

AND B.UNIT_NUMBER = C.UNIT_NUMBER

注意:每次DBMS_PROFILER.START_PROFILER的输入参数需要改变,否则便不能分别运行后的运行结果了。

除此之外B.UNIT_OWNER =‘’中的约束值如果是在package里面需要是包名,如果是procedure则是procedure的名字。实在在不知道什么名字时可以在PLSQL_PROFILER_UNITS中查一下。

此外,运行结果可以通过PLSQL Developer来观察,需要新建一个test,在profiler中可以查看它的运行结果,示例如下: