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Home -> Community -> Mailing Lists -> Oracle-L -> RE: data block waits
I'd like to jump in with my own issue...
Just for my own understanding; if my buffer busy waits where caused by
insufficient freelists
would I not see any free list waits ?
EVENT TIME_WAITED ---------------------------------------------------------------- ----------- CPU used by this session 6558085 db file sequential read 4637250 db file scattered read 4505090 buffer busy waits 416597 latch free 254869
wait events
CLASS COUNT TIME ------------------ ---------- ---------- data block 1108061 420097 sort block 0 0 save undo block 0 0 segment header 25 26 save undo header 0 0 free list 0 0 extent map 0 0 bitmap block 0 0 bitmap index block 0 0 unused 0 0 system undo header 0 0 system undo block 0 0 undo header 111 7 undo block 4255 4599
-----Original Message-----
From: Steve Adams [mailto:steve.adams_at_ixora.com.au]
Sent: September 01, 2000 8:50 AM
To: Multiple recipients of list ORACLE-L
Subject: RE: data block waits
Hi Jack,
A high 'CPU used by this session' value and relatively few waits indicate
that
the instance has been working hard but efficiently. It may be that the
instance
has been working unduly hard, but that cannot be determined from the
statistics
alone.
Your 'buffer busy waits' appear to be enough of a problem to be worth
fixing.
Yes, it is most likely that multiple process freelists are needed here.
@ Regards,
@ Steve Adams
@ http://www.ixora.com.au/
@ http://www.christianity.net.au/
@
@ Going to OpenWorld?
@ Catch the Ixora performance tuning seminar too!
@ See http://www.ixora.com.au/seminars/ for details.
-----Original Message-----
Sent: Friday, 1 September 2000 19:17
To: Multiple recipients of list ORACLE-L
Hi Steve,
Thx for your help.
Could a very high value also indicate another problem like badly written SQL-statements that take way too loooooong to complete.???
Also if somebody could let his/her mind wander over this list here
This is from v$waitstat and all waits are basically on one table only (thx
steve for the scripts on your website)
Is this the sort of 'problem' that can be solved by increasing the number
of freelists, or should I try to lower the number of rows per block (only 5
anyway for 8k block size)
And second is this a serious problem????
Database Date/Time
mm-dd hh:mi Data Block Blk Time
---------- ----------- ---------- ----------
PPRD 08-24 09:00 2204 6426
08-24 10:00 14577 1522
08-24 11:00 12850 1340
08-24 12:00 2415 1200
08-24 13:00 10693 779
08-24 14:00 14787 2777
08-24 15:00 6659 972
08-24 16:00 5427 704
08-24 17:00 636 266
08-24 18:00 4 0
08-24 19:02 3 1
08-24 20:00 2 0
08-24 21:00 1 0
08-24 22:00 0 0
08-25 08:00 1684 23055
08-25 09:00 1752 4409
08-25 10:00 1583 488
08-25 11:00 5563 1175
08-25 12:00 31641 5719
08-25 13:00 11495 2244
08-25 14:00 8055 1332
08-25 15:00 743 77
08-25 16:00 791 313
08-25 21:00 0 0
08-25 22:00 0 0
08-26 08:00 3 2
08-26 09:00 0 0
08-26 10:00 0 0
08-26 11:00 653 373
08-26 12:00 0 0
08-26 13:00 2 0
08-26 14:00 0 0
08-26 15:00 0 0
08-26 16:00 2 0
08-26 17:00 1 0
08-26 18:00 0 0
08-26 19:01 4 0
08-26 20:00 2 0
08-26 21:00 0 0
08-26 22:00 2 0
08-27 08:00 1761 11172
08-27 09:00 0 0
08-27 10:00 0 0
08-27 11:00 0 0
08-27 12:00 0 0
08-27 13:00 0 0
08-27 14:00 1 0
08-27 15:00 3 5
08-27 16:00 0 0
08-27 17:00 0 0
08-27 18:00 0 0
08-27 19:01 2 0
08-27 20:00 0 0
08-27 21:00 0 0
08-27 22:00 1 0
08-28 08:00 1900 26425
08-28 09:00 190 15
08-28 10:00 6596 12339
08-28 11:00 14510 9124
08-28 12:00 11986 24020
08-28 13:00 13542 4677
08-28 14:00 7014 3247
08-28 15:00 8170 1848
08-28 16:00 26382 8592
08-28 17:00 8587 1012
08-28 18:00 627 47
08-28 19:01 1 0
08-28 20:00 0 0
08-28 21:00 5 205
08-28 22:00 0 0
08-29 08:00 735 16316
08-29 09:00 2669 7424
08-29 10:00 1392 557
08-29 11:00 6118 7536
08-29 12:00 2837 860
08-29 13:00 2437 1540
08-29 14:00 2585 906
08-29 15:00 2526 1011
08-29 16:00 1803 1144
08-29 17:00 3610 1221
08-29 18:00 44 30
08-29 19:02 0 0
08-29 20:00 4 2
08-29 21:00 7 2
08-29 22:00 0 0
08-30 08:00 3468 12722
08-30 09:00 746 1871
08-30 10:00 6 0
08-30 11:00 610 562
08-30 12:00 437 44
08-30 13:00 36 69
08-30 14:00 1020 1389
08-30 15:00 868 317
08-30 16:00 758 108
08-30 17:00 369 121
08-30 18:00 33 22
08-30 19:01 17 17
08-30 20:00 1 0
08-30 21:00 2 0
08-30 22:00 1 0
08-31 08:00 2983 166476
08-31 09:00 6845 128959
08-31 10:00 945 900
08-31 11:00 2 1
08-31 12:00 425 146
08-31 13:00 4 0
08-31 14:00 172 180
08-31 15:00 64 62
08-31 16:00 635 226
08-31 17:00 391 69
08-31 18:00 59 68
08-31 19:02 2 1
08-31 20:00 279 470
08-31 21:00 0 0
08-31 22:00 1 0
09-01 08:00 637 5167
TIA JACK "Steve Adams" <steve.adams_at_ixora.com.au>@fatcity.com on 08/31/2000 08:46:51 AM
Please respond to ORACLE-L_at_fatcity.com
Sent by: root_at_fatcity.com
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com> cc:
Hi Jack,
That's good. It reflects the amount of time that you have spent using the
CPU to
do productive work, rather than waiting.
@ Regards,
@ Steve Adams
@ http://www.ixora.com.au/
@ http://www.christianity.net.au/
@
@ Going to OpenWorld?
@ Catch the Ixora performance tuning seminar too!
@ See http://www.ixora.com.au/seminars/ for details.
-----Original Message-----
Sent: Thursday, 31 August 2000 0:26
To: Multiple recipients of list ORACLE-L
Hi Steve,
Thought I'd run it in my databas eas well.
What does "CPU used by this session" mean, it's very high compared to the other events?
-- Author: Steve Adams INET: steve.adams_at_ixora.com.au Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail messageReceived on Tue Sep 05 2000 - 13:17:59 CDT
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