Oracle建议关闭自动统计任务中的STA以及段指导

Oracle建议关闭自动统计任务中的STA以及段指导

11g中默认启动了三个任务，分别是自动统计信息收集、自动段指导、STA，默认运行时间是周一到周五是运行4小时（22:00->次日2:00），周六日运行20小时（6:00->次日2:00）。

其中，STA以及段指导可以建议关闭，用处不大。而且必要时可以手工运行。

关于这几个任务的详细介绍网上够多就不介绍了。

查看任务状态：

col client_name for a35
select client_name,status from dba_autotask_client;

09:48:58 SYS@dbtest(826)> col client_name for a35
09:49:04 SYS@dbtest(826)> select client_name,status from dba_autotask_client;

CLIENT_NAME                         STATUS
----------------------------------- ----------
auto optimizer stats collection     ENABLED
auto space advisor                  ENABLED
sql tuning advisor                  ENABLED

禁用STA和段指导：

exec dbms_auto_task_admin.disable(client_name => 'sql tuning advisor',operation => NULL,window_name => NULL);

exec dbms_auto_task_admin.disable (client_name => 'auto space advisor', operation => null, window_name => null);
PL/SQL procedure successfully completed.

select client_name,status from dba_autotask_client;

14:47:39 SYS@testdb(1203)> exec dbms_auto_task_admin.disable(client_name => 'sql tuning advisor',operation => NULL,window_name => NULL);

PL/SQL procedure successfully completed.

Elapsed: 00:00:00.05
14:50:20 SYS@testdb(1203)> exec dbms_auto_task_admin.disable (client_name => 'auto space advisor', operation => null, window_name => null);

PL/SQL procedure successfully completed.

Elapsed: 00:00:00.00
15:02:28 SYS@testdb(1203)> select client_name,status from dba_autotask_client;

CLIENT_NAME                         STATUS
----------------------------------- ------------------------
auto optimizer stats collection     ENABLED
auto space advisor                  DISABLED
sql tuning advisor                  DISABLED

Elapsed: 00:00:00.28

查看自动统计任务的3个任务实际执行内容：

set line 500
col PROGRAM_NAME for a35
col PROGRAM_ACTION for a100
select program_name,program_action from dba_scheduler_programs where program_name in (select upper(task_name) from DBA_AUTOTASK_TASK);

17:08:56 SYS@testdb(89)> select program_name,program_action from dba_scheduler_programs where program_name in (select upper(task_name) from DBA_AUTOTASK_TASK);

PROGRAM_NAME                        PROGRAM_ACTION
----------------------------------- ----------------------------------------------------------------------------------------------------
AUTO_SQL_TUNING_PROG                DECLARE
                                             ename VARCHAR2(30);
                                           BEGIN
                                             ename := dbms_sqltune.execute_tuning_task(
                                                        'SYS_AUTO_SQL_TUNING_TASK');
                                           END;

AUTO_SPACE_ADVISOR_PROG             dbms_space.auto_space_advisor_job_proc
GATHER_STATS_PROG                   dbms_stats.gather_database_stats_job_proc

Elapsed: 00:00:00.01

因此有，

手工执行系统STA：

exec dbms_sqltune.execute_tuning_task('SYS_AUTO_SQL_TUNING_TASK');

查看STA结果：

select dbms_sqltune.report_tuning_task('SYS_AUTO_SQL_TUNING_TASK') from dual;

手工执行段指导：

exec dbms_space.auto_space_advisor_job_proc;

查询段指导结果：

select tablespace_name, segment_name, segment_type,
     recommendations, c1
     from table(dbms_space.asa_recommendations('TRUE', 'TRUE', 'FALSE'));