oracle 数据库性能监控的SQL 1. 监控事例的等待 SQL> SELECT EVENT,SUM(DECODE(WAIT_TIME,0,0,1)) "PREV",SUM(DECODE(WAIT_TIME,0,1,0)) "CURR",COUNT(*) "TOT" FROM V$SESSION_WAIT GROUP BY EVENT ORDER BY 4; 2. 回滚段的争用情况 SQL> SELECT NAME, WAITS, GETS, WAITS/GETS "RATIO" FROM V$ROLLSTAT A, V$ROLLNAME B WHERE A.USN = B.USN; 3. 监控表空间的 I/O 比例 SQL> SELECT DF.TABLESPACE_NAME NAME,DF.FILE_NAME "FILE",F.PHYRDS PYR, F.PHYBLKRD PBR,F.PHYWRTS PYW, F.PHYBLKWRT PBW FROM V$FILESTAT F, DBA_DATA_FILES DF WHERE F.FILE# = DF.FILE_ID ORDER BY DF.TABLESPACE_NAME; 4. 监控文件系统的 I/O 比例 SQL> SELECT SUBSTR(A.FILE#,1,2) "#", SUBSTR(A.NAME,1,30) "NAME", A.STATUS,A.BYTES,B.PHYRDS,B.PHYWRTS FROM V$DATAFILE A, V$FILESTAT B WHERE A.FILE# = B.FILE#; 5.在某个用户下找所有的索引 SQL> SELECT USER_INDEXES.TABLE_NAME, USER_INDEXES.INDEX_NAME,UNIQUENESS, COLUMN_NAME FROM USER_IND_COLUMNS, USER_INDEXES WHERE USER_IND_COLUMNS.INDEX_NAME = USER_INDEXES.INDEX_NAME AND USER_IND_COLUMNS.TABLE_NAME = USER_INDEXES.TABLE_NAME ORDER BY USER_INDEXES.TABLE_TYPE, USER_INDEXES.TABLE_NAME, USER_INDEXES.INDEX_NAME, COLUMN_POSITION; 6. 监控 SGA 的命中率 SQL> 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$SYSSTAT C WHERE A.STATISTIC# = 38 AND B.STATISTIC# = 39 AND C.STATISTIC# = 40; 7. 监控 SGA 中字典缓冲区的命中率 SQL> SELECT PARAMETER, GETS,GETMISSES , GETMISSES/(GETS+GETMISSES)*100 "MISS RATIO",(1-(SUM(GETMISSES)/ (SUM(GETS)+SUM(GETMISSES))))*100 "HIT RATIO" FROM V$ROWCACHE WHERE GETS+GETMISSES <>0 GROUP BY PARAMETER, GETS, GETMISSES; 8. 监控 SGA 中共享缓存区的命中率，应该小于1% SQL> SELECT SUM(PINS) "TOTAL PINS", SUM(RELOADS) "TOTAL RELOADS", SUM(RELOADS)/SUM(PINS) *100 LIBCACHE FROM V$LIBRARYC...
