在缺乏的可视化工具来监控数据库性能的情形下，常用的脚本就派上用场了，下面提供几个关于Oracle性能相关的脚本供大家参考。以下脚本均在Oracle 10g测试通过，Oracle 11g可能要做相应调整。
1、寻找最多BUFFER_GETS开销的SQL 语句
--filename: top_sql_by_buffer_gets.sql
--Identify heavy SQL (Get the SQL with heavy BUFFER_GETS)
SET LINESIZE 190
COL sql_text FORMAT a100 WRAP
SET PAGESIZE 100
SELECT *
FROM ( SELECT sql_text,
sql_id,
executions,
disk_reads,
buffer_gets
FROM v$sqlarea
WHERE DECODE (executions, 0, buffer_gets, buffer_gets / executions) >
(SELECT AVG (DECODE (executions, 0, buffer_gets, buffer_gets / executions))
+ STDDEV (DECODE (executions, 0, buffer_gets, buffer_gets / executions))
FROM v$sqlarea)
AND parsing_user_id != 3D
ORDER BY 5 DESC) x /*更正@20140613,原来为order by 4,感谢网友lmalds指正*/
WHERE ROWNUM <= 10;
2、寻找最多DISK_READS开销的SQL 语句
--filename:top_sql_disk_reads.sql
--Identify heavy SQL (Get the SQL with heavy DISK_READS)
SET LINESIZE 190
COL sql_text FORMAT a100 WRAP
SET PAGESIZE 100
SELECT *
FROM ( SELECT sql_text,
sql_id,
executions,
disk_reads,
buffer_gets
FROM v$sqlarea
WHERE DECODE (executions, 0, disk_reads, disk_reads / executions) >
(SELECT AVG (DECODE (executions, 0, disk_reads, disk_reads / executions))
+ STDDEV (DECODE (executions, 0, disk_reads, disk_reads / executions))
FROM v$sqlarea)
AND parsing_user_id != 3D
ORDER BY 4 DESC) x /* 更正@20140613,原来为order by 3,谢谢网友lmalds指正*/
WHERE ROWNUM <= 10;
3、寻找最近30分钟导致资源过高开销的事件
--filename:top_event_in_30_min.sql
--Last 30 minutes result those resources that are in high demand on your system.
SET LINESIZE 180
COL event FORMAT a60
COL total_wait_time FORMAT 999999999999999999
SELECT active_session_history.event,
SUM (
active_session_history.wait_time
+ active_session_history.time_waited)
total_wait_time
FROM v$active_session_history active_session_history
WHERE active_session_history.sample_time BETWEEN SYSDATE - 60 / 2880
AND SYSDATE
AND active_session_history.event IS NOT NULL
GROUP BY active_session_history.event
ORDER BY 2 DESC;
4、查找最近30分钟内等待最多的用户
--filename:top_wait_by_user.sql
--What user is waiting the most?
SET LINESIZE 180
COL event FORMAT a60
COL total_wait_time FORMAT 999999999999999999
SELECT ss.sid,
NVL (ss.username, 'oracle') AS username,
SUM (ash.wait_time + ash.time_waited) total_wait_time
FROM v$active_session_history ash, v$session ss
WHERE ash.sample_time BETWEEN SYSDATE - 60 / 2880 AND SYSDATE AND ash.session_id = ss.sid
GROUP BY ss.sid, ss.username
ORDER BY 3 DESC;
5、查找30分钟消耗最多资源的SQL语句
--filename:top_sql_by_wait.sql
-- What SQL is currently using the most resources?
SET LINESIZE 180
COL sql_text FORMAT a90 WRAP
COL username FORMAT a20 WRAP
SET PAGESIZE 200
SELECT *
FROM ( SELECT sqlarea.sql_text,
dba_users.username,
sqlarea.sql_id,
SUM (active_session_history.wait_time + active_session_history.time_waited)
total_wait_time
FROM v$active_session_history active_session_history, v$sqlarea sqlarea, dba_users
WHERE active_session_history.sample_time BETWEEN SYSDATE - 60 / 2880 AND SYSDATE
AND active_session_history.sql_id = sqlarea.sql_id
AND active_session_history.user_id = dba_users.user_id
GROUP BY active_session_history.user_id,
sqlarea.sql_text,
sqlarea.sql_id,
dba_users.username
ORDER BY 4 DESC) x
WHERE ROWNUM <= 11;
6、等待最多的对象
--filename:top_object_by_wait.sql
--What object is currently causing the highest resource waits?
SET LINESIZE 180
COLUMN OBJECT_NAME FORMAT a30
COLUMN EVENT FORMAT a30
SELECT dba_objects.object_name,
dba_objects.object_type,
active_session_history.event,
SUM (active_session_history.wait_time + active_session_history.time_waited) ttl_wait_time
FROM v$active_session_history active_session_history, dba_objects
WHERE active_session_history.sample_time BETWEEN SYSDATE - 60 / 2880 AND SYSDATE
AND active_session_history.current_obj# = dba_objects.object_id
GROUP BY dba_objects.object_name, dba_objects.object_type, active_session_history.event
ORDER BY 4 DESC;
7、寻找基于指定时间范围内的历史SQL语句
--注该查询受到awr快照相关参数的影响
-- filename:top_sql_in_spec_time.sql
--Top SQLs Elaps time and CPU time in a given time range..
--X.ELAPSED_TIME/1000000 => From Micro second to second
--X.ELAPSED_TIME/1000000/X.EXECUTIONS_DELTA => How many times the sql ran
SET PAUSE ON
SET PAUSE 'Press Return To Continue'
SET LINESIZE 180
COL sql_text FORMAT a80 WRAP
SELECT sql_text,
dhst.sql_id,
ROUND (x.elapsed_time / 1000000 / x.executions_delta, 3) elapsed_time_sec,
ROUND (x.cpu_time / 1000000 / x.executions_delta, 3) cpu_time_sec,
x.elapsed_time,
x.cpu_time,
executions_delta AS exec_delta
FROM dba_hist_sqltext dhst,
( SELECT dhss.sql_id sql_id,
SUM (dhss.cpu_time_delta) cpu_time,
SUM (dhss.elapsed_time_delta) elapsed_time,
CASE SUM (dhss.executions_delta) WHEN 0 THEN 1 ELSE SUM (dhss.executions_delta) END
AS executions_delta
FROM dba_hist_sqlstat dhss
WHERE dhss.snap_id IN
(SELECT snap_id
FROM dba_hist_snapshot
WHERE begin_interval_time >= TO_DATE ('&input_start_date', 'YYYYMMDD HH24:MI')
AND end_interval_time <= TO_DATE ('&input_end_date', 'YYYYMMDD HH24:MI'))
GROUP BY dhss.sql_id) x
WHERE x.sql_id = dhst.sql_id
ORDER BY elapsed_time_sec DESC;
8、寻找基于指定时间范围内及指定用户的历史SQL语句
--注该查询受到awr快照相关参数的影响
--Author : Robinson
--Blog : http://blog.csdn.net/robinson_0612
SELECT DBMS_LOB.SUBSTR (sql_text, 4000, 1) AS sql,
ROUND (x.elapsed_time / 1000000, 2) elapsed_time_sec,
ROUND (x.cpu_time / 1000000, 2) cpu_time_sec,
x.executions_delta AS exec_num,
ROUND ( (x.elapsed_time / 1000000) / x.executions_delta, 2) AS exec_time_per_query_sec
FROM dba_hist_sqltext dhst,
( SELECT dhss.sql_id sql_id,
SUM (dhss.cpu_time_delta) cpu_time,
SUM (dhss.elapsed_time_delta) elapsed_time,
CASE SUM (dhss.executions_delta) WHEN 0 THEN 1 ELSE SUM (dhss.executions_delta) END
AS executions_delta
--DHSS.EXECUTIONS_DELTA = No of queries execution (per hour)
FROM dba_hist_sqlstat dhss
WHERE dhss.snap_id IN
(SELECT snap_id
FROM dba_hist_snapshot
WHERE begin_interval_time >= TO_DATE ('&input_start_date', 'YYYYMMDD HH24:MI')
AND end_interval_time <= TO_DATE ('&input_end_date', 'YYYYMMDD HH24:MI'))
AND dhss.parsing_schema_name LIKE UPPER ('%&input_username%')
GROUP BY dhss.sql_id) x
WHERE x.sql_id = dhst.sql_id
ORDER BY elapsed_time_sec DESC;
9、SQL语句被执行的次数
--exe_delta表明在指定时间内增长的次数
-- filename: sql_exec_num.sql
-- How many Times a query executed?
SET LINESIZE 180
SET VERIFY OFF
SELECT TO_CHAR (s.begin_interval_time, 'yyyymmdd hh24:mi:ss'),
sql.sql_id AS sql_id,
sql.executions_delta AS exe_delta,
sql.executions_total
FROM dba_hist_sqlstat sql, dba_hist_snapshot s
WHERE sql_id = '&input_sql_id'
AND s.snap_id = sql.snap_id
AND s.begin_interval_time > TO_DATE ('&input_start_date', 'YYYYMMDD HH24:MI')
AND s.begin_interval_time < TO_DATE ('&input_end_date', 'YYYYMMDD HH24:MI')
ORDER BY s.begin_interval_time;
更多参考
PL/SQL 联合数组与嵌套表
PL/SQL 变长数组
PL/SQL --> PL/SQL记录
