如何关闭统计信息自动分析？

Oracle 10g中默认是对统计信息自动进行分析，每天22：00会启动一个scheduler job来来进行，自动分析并不是说每天都去分析一遍所有表，只是分析rows改变超过10%的表，这是合理的，只分析很少一部分表。当然任何新特性存在都会有一定缺陷，关键看我们怎么来用这个功能，至于是否要关闭自动分析，就要看你的需求和使用情况了。

--检查是否开启了自动分析

    SQL> select t.owner,t.job_name,t.last_start_date,t.last_run_duration,t.next_run_date,t.comments

     2 from dba_scheduler_jobs t where t.comments like \'%statistics collection%\'

     3 ;

OWNER JOB_NAME LAST_START_DATE LAST_RUN_DURATION NEXT_RUN_DATE COMMENTS

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

    SYS GATHER_STATS_JOB 17-OCT-07 10.00.03.137638 PM +08:00 +000000000 00:02:17.909439 Oracle defined automatic optimizer statistics collection job

SQL>

--关闭自动分析

    db158:/home/oracle>$sqlplus "/ as sysdba"

SQL*Plus: Release 10.2.0.3.0 - Production on Thu Oct 18 14:53:36 2007

Copyright (c) 1982, 2006, Oracle. All Rights Reserved.

    Connected to:

    Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production

    With the Partitioning, OLAP and Data Mining options

SQL> exec dbms_scheduler.disable(\'SYS.GATHER_STATS_JOB\') ;

PL/SQL procedure successfully completed.

--打开自动分析

    SQL> exec dbms_scheduler.enable(\'SYS.GATHER_STATS_JOB\') ;

PL/SQL procedure successfully completed.

具体的参考: