调整统计信息JOB采样时间

一、需求说明

Oracle数据库中存在定时JOB,自动执行收集统计信息的程序。但是对于7*24小时系统来说，Oracle配置的定时收集时间不太合理，需要人为调整。本篇博客就是基于这种需求，调整JOB采样的时间及终止时间。

思路：查询现有的默认收集统计信息的策略，对它进行调整，调整后进行检查修改有效，操作完毕。

二、操作步骤

2.1 修改前，查询JOB信息

查询数据库自动收集统计信息是否被禁用

SQL> select client_name,status from dba_autotask_client;

CLIENT_NAME STATUS
---------------------------------------------------------------- --------
auto optimizer stats collection ENABLED

数据库默认，周一~周五(每天晚上10点开始，收集6小时截止）、周六日(每天早上6点开始，收集20小时截止)
SQL> select t1.window_name,t1.repeat_interval,t1.duration from dba_scheduler_windows t1,dba_scheduler_wingroup_members t2
where t1.window_name=t2.window_name and t2.window_group_name in ('MAINTENANCE_WINDOW_GROUP','BSLN_MAINTAIN_STATS_SCHED');

WINDOW_NAME    REPEAT_INTERVAL    DURATION
-------------------- ------------------------------------------------------- ----------------------------------------------------
SATURDAY_WINDOW freq=daily;byday=SAT;byhour=;byminute=; bysecond= + ::
FRIDAY_WINDOW    freq=daily;byday=FRI;byhour=;byminute=; bysecond= + ::
THURSDAY_WINDOW freq=daily;byday=THU;byhour=;byminute=; bysecond= + ::
WEDNESDAY_WINDOW freq=daily;byday=WED;byhour=;byminute=; bysecond= + ::
TUESDAY_WINDOW    freq=daily;byday=TUE;byhour=;byminute=; bysecond= + ::
MONDAY_WINDOW    freq=daily;byday=MON;byhour=;byminute=; bysecond= + ::
SUNDAY_WINDOW    freq=daily;byday=SUN;byhour=;byminute=; bysecond= + ::
 rows selected.

2.2 修改操作

--周六日统计信息收集最长时间调整为4小时
BEGIN
dbms_scheduler.disable(
name => 'SATURDAY_WINDOW');
dbms_scheduler.set_attribute(
name => 'SATURDAY_WINDOW',
attribute => 'DURATION',
value => numtodsinterval(, 'hour'));
dbms_scheduler.enable(
name => 'SATURDAY_WINDOW');
END;
/

BEGIN
dbms_scheduler.disable(
name => 'SUNDAY_WINDOW');
dbms_scheduler.set_attribute(
name => 'SUNDAY_WINDOW',
attribute => 'DURATION',
value => numtodsinterval(, 'hour'));
dbms_scheduler.enable(
name => 'SUNDAY_WINDOW');
END;
/
commit;

--

--统计信息开始收集时间调整
周一-周五，调整为0点开始

BEGIN
DBMS_SCHEDULER.SET_ATTRIBUTE(
name=>'"SYS"."MONDAY_WINDOW"',
attribute=>'REPEAT_INTERVAL',
value=>'FREQ=WEEKLY;BYDAY=MON;BYHOUR=0;BYMINUTE=0;BYSECOND=0');
END;
/

BEGIN
DBMS_SCHEDULER.SET_ATTRIBUTE(
name=>'"SYS"."TUESDAY_WINDOW"',
attribute=>'REPEAT_INTERVAL',
value=>'FREQ=WEEKLY;BYDAY=TUE;BYHOUR=0;BYMINUTE=0;BYSECOND=0');
END;
/

BEGIN
DBMS_SCHEDULER.SET_ATTRIBUTE(
name=>'"SYS"."WEDNESDAY_WINDOW"',
attribute=>'REPEAT_INTERVAL',
value=>'FREQ=WEEKLY;BYDAY=WED;BYHOUR=0;BYMINUTE=0;BYSECOND=0');
END;
/

BEGIN
DBMS_SCHEDULER.SET_ATTRIBUTE(
name=>'"SYS"."THURSDAY_WINDOW"',
attribute=>'REPEAT_INTERVAL',
value=>'FREQ=WEEKLY;BYDAY=THU;BYHOUR=0;BYMINUTE=0;BYSECOND=0');
END;
/

BEGIN
DBMS_SCHEDULER.SET_ATTRIBUTE(
name=>'"SYS"."FRIDAY_WINDOW"',
attribute=>'REPEAT_INTERVAL',
value=>'FREQ=WEEKLY;BYDAY=FRI;BYHOUR=0;BYMINUTE=0;BYSECOND=0');
END;
/

BEGIN
DBMS_SCHEDULER.SET_ATTRIBUTE(
name=>'"SYS"."SATURDAY_WINDOW"',
attribute=>'REPEAT_INTERVAL',
value=>'FREQ=WEEKLY;BYDAY=SAT;BYHOUR=0;BYMINUTE=0;BYSECOND=0');
END;
/

BEGIN
DBMS_SCHEDULER.SET_ATTRIBUTE(
name=>'"SYS"."SUNDAY_WINDOW"',
attribute=>'REPEAT_INTERVAL',
value=>'FREQ=WEEKLY;BYDAY=SUN;BYHOUR=0;BYMINUTE=0;BYSECOND=0');
END;
/

SQL> commit;

2.3  修改后检查

SQL> select t1.window_name,t1.repeat_interval,t1.duration from dba_scheduler_windows t1,dba_scheduler_wingroup_members t2
where t1.window_name=t2.window_name and t2.window_group_name in ('MAINTENANCE_WINDOW_GROUP','BSLN_MAINTAIN_STATS_SCHED'); 

WINDOW_NAME    REPEAT_INTERVAL    DURATION
-------------------- ------------------------------------------------------- ----------------------------------------------
SATURDAY_WINDOW FREQ=WEEKLY;BYDAY=SAT;BYHOUR=;BYMINUTE=;BYSECOND= + ::
FRIDAY_WINDOW    FREQ=WEEKLY;BYDAY=FRI;BYHOUR=;BYMINUTE=;BYSECOND= + ::
THURSDAY_WINDOW FREQ=WEEKLY;BYDAY=THU;BYHOUR=;BYMINUTE=;BYSECOND= + ::
WEDNESDAY_WINDOW FREQ=WEEKLY;BYDAY=WED;BYHOUR=;BYMINUTE=;BYSECOND= + ::
TUESDAY_WINDOW    FREQ=WEEKLY;BYDAY=TUE;BYHOUR=;BYMINUTE=;BYSECOND= + ::
MONDAY_WINDOW    FREQ=WEEKLY;BYDAY=MON;BYHOUR=;BYMINUTE=;BYSECOND= + ::
SUNDAY_WINDOW    FREQ=WEEKLY;BYDAY=SUN;BYHOUR=;BYMINUTE=;BYSECOND= + ::

 rows selected.

SQL> select WINDOW_NAME,to_char(WINDOW_START_TIME,'yyyy-mm-dd hh24:mi:ss'),to_char(WINDOW_END_TIME,'yyyy-mm-dd hh24:mi:ss')
 from dba_autotask_window_history order by ;

WINDOW_NAME    TO_CHAR(WINDOW_STAR TO_CHAR(WINDOW_END_
-------------------- ------------------- -------------------
FRIDAY_WINDOW    -- :: -- ::
SATURDAY_WINDOW -- :: -- ::
SUNDAY_WINDOW    -- :: -- ::
MONDAY_WINDOW    -- :: -- ::
TUESDAY_WINDOW    -- :: -- ::
WEDNESDAY_WINDOW -- :: -- ::
THURSDAY_WINDOW -- :: -- ::
FRIDAY_WINDOW    -- :: -- ::
SATURDAY_WINDOW -- :: -- ::
SUNDAY_WINDOW    -- :: -- ::
MONDAY_WINDOW    -- :: -- ::

WINDOW_NAME    TO_CHAR(WINDOW_STAR TO_CHAR(WINDOW_END_
-------------------- ------------------- -------------------
TUESDAY_WINDOW    -- :: -- ::
WEDNESDAY_WINDOW -- :: -- ::
THURSDAY_WINDOW -- :: -- ::
FRIDAY_WINDOW    -- :: -- ::
SATURDAY_WINDOW -- :: -- ::
SUNDAY_WINDOW    -- :: -- ::
MONDAY_WINDOW    -- :: -- ::
TUESDAY_WINDOW    -- :: -- ::
WEDNESDAY_WINDOW -- :: -- ::
THURSDAY_WINDOW -- :: -- ::
FRIDAY_WINDOW    -- :: -- ::

WINDOW_NAME    TO_CHAR(WINDOW_STAR TO_CHAR(WINDOW_END_
-------------------- ------------------- -------------------
SATURDAY_WINDOW -- :: -- ::
SUNDAY_WINDOW    -- :: -- ::
MONDAY_WINDOW    -- :: -- ::
TUESDAY_WINDOW    -- :: -- ::
WEDNESDAY_WINDOW -- :: -- ::
THURSDAY_WINDOW -- :: -- ::
SATURDAY_WINDOW -- :: -- ::
SUNDAY_WINDOW    -- :: -- ::
MONDAY_WINDOW    -- :: -- ::

 rows selected.

2.4 补充关闭其余JOB

说明,Oracle数据库,除自动收集统计信息JOB外，还有关于SQL调优建议JOB SQL TUNING,以及段分析JOB，实际工作很少使用，建议关闭。

SQL> select client_name,status from dba_autotask_client;

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

BEGIN
dbms_auto_task_admin.disable(client_name=>'sql tuning advisor',operation=>NULL,window_name=>NULL);
END;
/
commit;

BEGIN
dbms_auto_task_admin.disable(client_name=>'auto space advisor',operation=>NULL,window_name=>NULL);
END;
/
commit;

SQL> select client_name,status from dba_autotask_client;
CLIENT_NAME    STATUS
---------------------------------------------------------------- --------
auto optimizer stats collection ENABLED
auto space advisor    DISABLED
sql tuning advisor    DISABLED