Oracle 常用性能监控SQL语句

原文：http://panhongbin100.iteye.com/blog/1596414

1. –查看表锁

SELECT * FROM SYS.V_SQLAREAWHEREDISKREADS>100;2.–监控事例的等待SELECTEVENT,SUM(DECODE(WAITTIME,0,0,1))“Prev”,SUM(DECODE(WAITTIME,0,1,0))“Curr”,COUNT(∗)“Tot”FROMVSESSION_WAIT

GROUP BY EVENT

ORDER BY 4;

3. –回滚段的争用情况

SELECT NAME, WAITS, GETS, WAITS / GETS “Ratio”

FROM VROLLSTATA,VROLLNAME B

WHERE A.USN = B.USN;

4. –查看前台正在发出的SQL语句

SELECT USER_NAME, SQL_TEXT 　　

FROM VOPEN_CURSOR 　　
WHERE SID IN (SELECT SID
&n
227e8
bsp; FROM (SELECT SID, SERIAL#, USERNAME, PROGRAM 　　
FROM VSESSION 　　

WHERE STATUS = ‘ACTIVE’));

5. –数据表占用空间大小情况

SELECT SEGMENT_NAME, TABLESPACE_NAME, BYTES, BLOCKS

FROM USER_SEGMENTS

WHERE SEGMENT_TYPE = ‘TABLE’

ORDER BY BYTES DESC, BLOCKS DESC;

6. –查看表空间碎片大小

SELECT TABLESPACE_NAME,

ROUND(SQRT(MAX(BLOCKS) / SUM(BLOCKS)) *

(100 / SQRT(SQRT(COUNT(BLOCKS)))),

2) FSFI

FROM DBA_FREE_SPACE

GROUP BY TABLESPACE_NAME

ORDER BY 1;

7. –查看表空间占用磁盘情况

SELECT B.FILE_ID 文件ID号,

B.TABLESPACE_NAME 表空间名,

B.BYTES 字节数,

(B.BYTES - SUM(NVL(A.BYTES, 0))) 已使用,

SUM(NVL(A.BYTES, 0)) 剩余空间,

SUM(NVL(A.BYTES, 0)) / (B.BYTES) * 100 剩余百分比

FROM DBA_FREE_SPACE A, DBA_DATA_FILES B

WHERE A.FILE_ID = B.FILE_ID

GROUP BY B.TABLESPACE_NAME, B.FILE_ID, B.BYTES

ORDER BY B.FILE_ID;

8. –查看session使用回滚段

SELECT R.NAME 回滚段名,

S.SID,

S.SERIAL#,

S.USERNAME 用户名,

T.STATUS,

T.CR_GET,

T.PHY_IO,

T.USED_UBLK,

T.NOUNDO,

SUBSTR(S.PROGRAM, 1, 78) 操作程序

FROM SYS.V_SESSION S, SYS.V_TRANSACTION T, SYS.V_ROLLNAME R
WHERE T.ADDR = S.TADDR
AND T.XIDUSN = R.USN
ORDER BY T.CR_GET, T.PHY_IO;
9. –查看SGA区剩余可用内存
SELECT NAME,
　　　　　　SGASIZE / 1024 / 1024　　　　　　　　“Allocated(M)”,
　　　　　　BYTES / 1024　　　　　　　　　　　 “**空间(K)”,
　　　　　　ROUND(BYTES / SGASIZE * 100, 2) 　　　“**空间百分比(%)” 　　
FROM (SELECT SUM(BYTES) SGASIZE FROM SYS.V_SGASTAT) S,

SYS.V_SGASTATF　　WHEREF.NAME=‘freememory′;10.–监控表空间I/O比例SELECTDF.TABLESPACENAMENAME,DF.FILENAME“file”,F.PHYRDSPYR,F.PHYBLKRDPBR,F.PHYWRTSPYW,F.PHYBLKWRTPBWFROMVFILESTAT F, DBA_DATA_FILES DF

WHERE F.FILE# = DF.FILE_ID

ORDER BY DF.TABLESPACE_NAME;

11. –监控SGA命中率

SELECT A.VALUE + B.VALUE “logical_reads”,

C.VALUE “phys_reads”,

ROUND(100 * ((A.VALUE + B.VALUE) - C.VALUE) / (A.VALUE + B.VALUE)) “BUFFER HIT RATIO”

FROM VSYSSTATA,VSYSSTAT B, VSYSSTAT C
WHERE A.STATISTIC# = 38
AND B.STATISTIC# = 39
AND C.STATISTIC# = 40;
12. –监控 SGA 中字典缓冲区的命中率
SELECT PARAMETER,
GETS,
GETMISSES,
GETMISSES / (GETS + GETMISSES) * 100 “miss ratio”,
(1 - (SUM(GETMISSES) / (SUM(GETS) + SUM(GETMISSES)))) * 100 “Hit ratio”
FROM VROWCACHE

WHERE GETS + GETMISSES <> 0

GROUP BY PARAMETER, GETS, GETMISSES;

13. –监控 SGA **享缓存区的命中率，应该小于1%

SELECT SUM(PINS) “Total Pins”,

SUM(RELOADS) “Total Reloads”,

SUM(RELOADS) / SUM(PINS) * 100 LIBCACHE

FROM VLIBRARYCACHE;14.–监控SGA中重做日志缓存区的命中率，应该小于1SELECTNAME,GETS,MISSES,IMMEDIATEGETS,IMMEDIATEMISSES,DECODE(GETS,0,0,MISSES/GETS∗100)RATIO1,DECODE(IMMEDIATEGETS+IMMEDIATEMISSES,0,0,IMMEDIATEMISSES/(IMMEDIATEGETS+IMMEDIATEMISSES)∗100)RATIO2FROMVLATCH

WHERE NAME IN (‘redo allocation’, ‘redo copy’);

15. –监控内存和硬盘的排序比率，最好使它小于 .10

SELECT NAME, VALUE

FROM VSYSSTATWHERENAMEIN(‘sorts(memory)′,‘sorts(disk)′);16.–监控字典缓冲区SELECTSUM(GETS)“DICTIONARYGETS”,SUM(GETMISSES)“DICTIONARYCACHEGETMISSES”FROMVROWCACHE;

17. –非系统用户建在SYSTEM表空间中的表

SELECT OWNER, TABLE_NAME

FROM DBA_TABLES

WHERE TABLESPACE_NAME IN (‘SYSTEM’, ‘USER_DATA’)

AND OWNER NOT IN

(‘SYSTEM’, ‘SYS’, ‘OUTLN’, ‘ORDSYS’, ‘MDSYS’, ‘SCOTT’, ‘HOSTEAC’);

18. –性能最差的SQL

SELECT *

FROM (SELECT PARSING_USER_ID EXECUTIONS,

SORTS,

COMMAND_TYPE,

DISK_READS,

SQL_TEXT

FROM V$SQLAREA

ORDER BY DISK_READS DESC)

WHERE ROWNUM < 100;

–用下列SQL 工具找出低效SQL ：

SELECT EXECUTIONS,

DISK_READS,

BUFFER_GETS,

ROUND((BUFFER_GETS - DISK_READS) / BUFFER_GETS, 2) HIT_RADIO,

ROUND(DISK_READS / EXECUTIONS, 2) READS_PER_RUN,

SQL_TEXT

FROM V$SQLAREA

WHERE EXECUTIONS > 0

AND BUFFER_GETS > 0

AND (BUFFER_GETS - DISK_READS) / BUFFER_GETS < 0.8

ORDER BY 4 DESC;

–读磁盘数超100次的sql

SELECT * FROM SYS.V_$SQLAREA WHERE DISK_READS > 100;

–最频繁执行的sql

SELECT * FROM SYS.V_$SQLAREA WHERE EXECUTIONS > 100;

–查询使用CPU多的用户session

SELECT A.SID,

SPID,

STATUS,

SUBSTR(A.PROGRAM, 1, 40) PROG,

A.TERMINAL,

OSUSER,

VALUE / 60 / 100 VALUE

FROM VSESSIONA,VPROCESS B, V$SESSTAT C

WHERE C.STATISTIC# = 12

AND C.SID = A.SID

AND A.PADDR = B.ADDR

ORDER BY VALUE DESC;

–当前每个会话使用的对象数

SELECT A.SID, S.TERMINAL, S.PROGRAM, COUNT(A.SID)

FROM VACCESSA,VSESSION S

WHERE A.OWNER <> ‘SYS’

AND S.SID = A.SID

GROUP BY A.SID, S.TERMINAL, S.PROGRAM

ORDER BY COUNT(A.SID);