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Oracle種常用性能監控SQL語句

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--Oracle常用性能監控SQL語句
--1
SELECT * FROM SYS.V_$SQLAREA WHERE DISK_READS > 100;

--2 監控事例的等待
SELECT EVENT,
SUM(DECODE(WAIT_TIME, 0, 0, 1)) "Prev",
SUM(DECODE(WAIT_TIME, 0, 1, 0)) "Curr",
COUNT(*) "Tot"
FROM V$SESSION_WAIT
GROUP BY EVENT
ORDER BY 4;


--3 回滾段的爭用情況
SELECT NAME, WAITS, GETS, WAITS / GETS "Ratio"
FROM V$ROLLSTAT A, V$ROLLNAME B
WHERE A.USN = B.USN;


--4 查看前臺正在發出的SQL語句
SELECT USER_NAME, SQL_TEXT   
FROM V$OPEN_CURSOR   
WHERE SID IN (SELECT SID
FROM (SELECT SID, SERIAL#
, USERNAME, PROGRAM   
FROM V$SESSION   
WHERE STATUS = ‘ACTIVE‘));


--5 數據表占用空間大小情況
SELECT SEGMENT_NAME, TABLESPACE_NAME, BYTES, BLOCKS
FROM USER_SEGMENTS
WHERE SEGMENT_TYPE = ‘TABLE‘
ORDER BY BYTES DESC, BLOCKS DESC;


--6 查看表空間碎片大小
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 查看表空間占用磁盤情況
SELECT B.FILE_ID "文件ID號",
B.TABLESPACE_NAME "表空間名稱",
round(B.BYTES / (1024 * 1024), 2) "總空間(M)",
round((B.BYTES - SUM(NVL(A.BYTES, 0))) / (1024 * 1024), 2) "已使用剩余空間(M)",
round(SUM(NVL(A.BYTES, 0)) / (1024 * 1024), 2) "剩余空間(M)",
round(SUM(NVL(A.BYTES, 0)) / (B.BYTES) * 100, 2) "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使用回滾段
SELECT R.NAME 回滾段名,
S.SID,
S.SERIAL#,
S.USERNAME 用戶名,
T.STATUS,
T.CR_GET,
T.PHY_IO,
T.USED_UBLK,
T.NOUNDO,
SUBSTR(S.PROGRAM, 1, 78) as "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區剩余可用內存
SELECT NAME,
      SGASIZE / 1024 / 1024 as "Allocated(M)",
      BYTES / 1024 as "**空間(K)",
      ROUND(BYTES / SGASIZE * 100, 2) as "**空間百分比(%)"   
FROM (SELECT SUM(BYTES) SGASIZE FROM SYS.V_$SGASTAT) S,
SYS.V_$SGASTAT F   
WHERE F.NAME = ‘free memory‘;


--10 監控表空間I/O比例
SELECT DF.TABLESPACE_NAME NAME,
DF.FILE_NAME "file",
F.PHYRDS PYR,
F.PHYBLKRD PBR,
F.PHYWRTS PYW,
F.PHYBLKWRT PBW
FROM V$FILESTAT F, DBA_DATA_FILES DF
WHERE F.FILE# = DF.FILE_ID
ORDER BY DF.TABLESPACE_NAME;


--11 監控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 V$SYSSTAT A, V$SYSSTAT B, V$SYSSTAT C
WHERE A.STATISTIC# = 38
AND B.STATISTIC# = 39
AND C.STATISTIC# = 40;


--12 監控 SGA 中字典緩沖區的命中率
SELECT PARAMETER,
GETS,
GETMISSES,
GETMISSES / (GETS + GETMISSES) * 100 "miss ratio",
(1 - (SUM(GETMISSES) / (SUM(GETS) + SUM(GETMISSES)))) * 100 "Hit ratio"
FROM V$ROWCACHE
WHERE GETS + GETMISSES <> 0
GROUP BY PARAMETER, GETS, GETMISSES;


--13 監控 SGA **享緩存區的命中率,應該小於1%
SELECT SUM(PINS) "Total Pins",
SUM(RELOADS) "Total Reloads",
SUM(RELOADS) / SUM(PINS) * 100 LIBCACHE
FROM V$LIBRARYCACHE;


--14 監控 SGA 中重做日誌緩存區的命中率,應該小於1%
SELECT NAME,
GETS,
MISSES,
IMMEDIATE_GETS,
IMMEDIATE_MISSES,
DECODE(GETS, 0, 0, MISSES / GETS * 100) RATIO1,
DECODE(IMMEDIATE_GETS + IMMEDIATE_MISSES,
0,
0,
IMMEDIATE_MISSES / (IMMEDIATE_GETS + IMMEDIATE_MISSES) * 100) RATIO2
FROM V$LATCH
WHERE NAME IN (‘redo allocation‘, ‘redo copy‘);


--15 監控內存和硬盤的排序比率,最好使它小於 .10
SELECT NAME, VALUE
FROM V$SYSSTAT
WHERE NAME IN (‘sorts (memory)‘, ‘sorts (disk)‘);


--16 監控字典緩沖區
SELECT SUM(GETS) "DICTIONARY GETS",
SUM(GETMISSES) "DICTIONARY CACHE GET MISSES"
FROM V$ROWCACHE;


--17 非系統用戶建在SYSTEM表空間中的表
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;


--19 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;

--20 讀磁盤數超100次的sql
SELECT * FROM SYS.V_$SQLAREA WHERE DISK_READS > 100;


--21 最頻繁執行的sql
SELECT * FROM SYS.V_$SQLAREA WHERE EXECUTIONS > 100;


--22 查詢使用cpu多的用戶session
select vs.sid,
vs.SQL_ID,
vs.MACHINE,
vp.spid,
vs.status,
substr(vs.program, 1, 40) prog,
vs.terminal,
vs.osuser,
round(vstat.value / 60 * 100, 6) value
from v$session vs, v$process vp, v$sesstat vstat
where vstat.statistic# = 12
and vstat.sid = vs.sid
and vs.paddr = vp.addr
order by value desc;


--23 當前每個會話使用的對象數
SELECT A.SID, S.TERMINAL, S.PROGRAM, COUNT(A.SID)
FROM V$ACCESS A, V$SESSION S
WHERE A.OWNER <> ‘SYS‘
AND S.SID = A.SID
GROUP BY A.SID, S.TERMINAL, S.PROGRAM
ORDER BY COUNT(A.SID);

Oracle種常用性能監控SQL語句