O objetivo deste select é facilitar a identificação excessiva de eventos em espera.
A análise da view v$system_event será analisado as seguintes colunas:
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EVENT = nome do evento de espera TOTAL_WAITS = Número total de esperas para o evento TIME_WAITED = Tempo total esperado pelo evento (em centésimos de segundo) TOTAL_TIMEOUTS = Número total de tempos limite do evento AVERAGE_WAIT = Quantidade média de tempo esperada pelo evento (em centésimos de segundo) |
Select consultando view v$system_event
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set pages 999 set lines 90 column c1 heading 'Event|Name' format a30 column c2 heading 'Total|Waits' format 999,999,999 column c3 heading 'Seconds|Waiting' format 999,999 column c4 heading 'Total|Timeouts' format 999,999,999 column c5 heading 'Average|Wait|(in secs)' format 99.999 ttitle 'System-wide Wait Analysis|for current wait events select event c1, total_waits c2, time_waited / 100 c3, total_timeouts c4, average_wait /100 c5 from sys.v_$system_event where event not in ( 'dispatcher timer', 'lock element cleanup', 'Null event', 'parallel query dequeue wait', 'parallel query idle wait - Slaves', 'pipe get', 'PL/SQL lock timer', 'pmon timer', 'rdbms ipc message', 'slave wait', 'smon timer', 'SQL*Net break/reset to client', 'SQL*Net message from client', 'SQL*Net message to client', 'SQL*Net more data to client', 'virtual circuit status', 'WMON goes to sleep' ) AND event not like 'DFS%' and event not like '%done%' and event not like '%Idle%' AND event not like 'KXFX%' order by c2 desc ; |
Resultado.
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Event Total Seconds Total Wait Name Waits Waiting Timeouts (in secs) ------------------------------ ------------ -------- ------------ --------- PGA memory operation 4,610,093 80 0 .000 log file parallel write 612,773 8,631 0 .014 log file sync 595,143 8,682 0 .015 control file sequential read 472,261 7 0 .000 LGWR worker group idle 258,156 144,425 0 .559 jobq slave wait 227,071 112,822 224,079 .497 DIAG idle wait 149,646 149,635 149,643 1.000 Disk file operations I/O 106,913 85 0 .001 log file sequential read 91,427 121 0 .001 wait for unread message on bro 74,945 74,951 74,945 1.000 adcast channel heartbeat redo informer 74,928 74,944 0 1.000 Space Manager: slave idle wait 73,101 331,945 0 4.541 watchdog main loop 49,958 149,858 0 3.000 ADR block file read 34,627 170 0 .005 db file sequential read 32,187 36 0 .001 control file parallel write 31,542 2,142 0 .068 LGWR all worker groups 27,558 525 0 .019 pman timer 24,983 74,943 24,981 3.000 OFS idle 24,982 74,951 24,981 3.000 lreg timer 24,961 74,947 24,957 3.003 db file async I/O submit 8,594 252 0 .029 asynch descriptor resize 8,346 0 8,346 .000 os thread creation 8,309 15 0 .002 oracle thread bootstrap 8,307 173 0 .021 LGWR any worker group 5,819 145 0 .025 Streams AQ: qmn coordinator id 5,417 74,933 1 13.833 le wait class slave wait 5,343 1 0 .000 db file scattered read 4,155 5 0 .001 SQL*Net vector data to client 2,954 0 0 .000 Streams AQ: qmn slave idle wai 2,743 74,933 0 27.318 t reliable message 2,690 1 0 .000 get branch/thread/sequence enq 2,671 0 0 .000 ueue Data Guard: Timer 2,500 74,939 0 29.976 AQPC idle 2,498 74,923 2,497 29.993 latch free 2,264 0 0 .000 LGWR worker group ordering 1,969 12 0 .006 Log archive I/O 1,806 2 0 .001 Log file init write 1,806 3 0 .002 direct path read 1,295 0 0 .000 Data Guard: Gap Manager 1,250 74,942 0 59.954 db file single write 1,014 2 0 .002 SQL*Net more data from client 718 1 0 .001 enq: CR - block range reuse ck 650 20 0 .031 pt row cache mutex 633 0 0 .000 LGWR wait for redo copy 316 0 0 .000 latch: shared pool 281 0 0 .000 Compression analysis 264 0 0 .000 buffer busy waits 232 0 0 .000 log file single write 215 0 0 .002 enq: JG - queue lock 204 1 0 .003 library cache: mutex X 200 0 0 .000 Parameter File I/O 114 0 0 .000 kdic_do_merge 102 0 0 .000 latch: In memory undo latch 94 0 0 .000 enq: RO - fast object reuse 91 0 0 .000 enq: CF - contention 89 27 0 .303 ADR file lock 86 0 0 .000 Redo Transport Open 78 0 0 .000 switch logfile command 71 134 0 1.889 rdbms ipc reply 69 1 0 .008 ADR block file write 65 0 0 .001 log buffer space 54 21 0 .392 enq: PR - contention 51 1 0 .020 row cache read 47 0 0 .000 latch: cache buffers chains 42 0 0 .000 log file switch (checkpoint in 35 1 0 .027 complete) undo segment extension 23 0 22 .011 cursor: pin S 22 0 0 .001 row cache lock 22 0 0 .002 control file single write 21 1 0 .027 latch: call allocation 20 0 0 .000 utl_file I/O 19 0 0 .000 direct path write 19 0 0 .004 Failed Logon Delay 18 18 18 1.000 log file switch completion 18 0 0 .023 RMAN backup & recovery I/O 16 0 0 .002 log file switch (private stran 15 3 0 .198 d flush incomplete) cursor: pin S wait on X 15 0 0 .026 db file parallel read 13 0 0 .001 external table write 12 0 0 .000 latch: redo allocation 11 0 0 .001 library cache load lock 11 0 0 .004 library cache: bucket mutex X 10 0 0 .000 CSS initialization 7 0 0 .004 ASM file metadata operation 6 0 0 .000 read by other session 5 0 0 .000 resmgr:internal state change 5 1 1 .100 enq: SQ - contention 4 0 0 .000 local write wait 4 0 0 .003 direct path sync 4 0 0 .000 Data file init write 4 0 0 .003 latch: enqueue hash chains 4 0 0 .000 ksdxexeotherwait 4 0 0 .058 KSV master wait 3 0 3 .000 library cache lock 3 0 0 .002 AQ Background Master: slave st 2 0 0 .002 art latch: messages 2 0 0 .000 external table open 2 0 0 .002 AQPC: new master 2 0 0 .000 latch: redo writing 2 0 0 .000 instance state change 2 0 0 .000 shared server idle wait 2 74,996 0 ####### latch: active service list 2 0 0 .000 Streams AQ: load balancer idle 1 45 1 45.000 external table read 1 2 0 2.121 library cache pin 1 0 0 .016 enq: TX - contention 1 0 0 .008 CRS call completion 1 0 0 .004 cursor: mutex X 1 0 0 .000 resmgr:plan change 1 0 0 .005 control file heartbeat 1 4 1 4.000 SGA: allocation forcing compon 1 0 0 .148 ent growth DLM cross inst call completion 1 0 0 .001 enq: TX - row lock contention 1 18 0 18.270 enq: PV - syncstart 1 0 0 .019 enq: HW - contention 1 0 0 .016 116 rows selected. |
Fonte:dba-oracle.com , Oracle.com