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
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 4 DESC) x
WHERE ROWNUM
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 3 DESC) x
WHERE ROWNUM
