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RE: data block waits

From: Steve Adams <steve.adams_at_ixora.com.au>
Date: Fri, 1 Sep 2000 21:47:51 +1000
Message-Id: <10606.116062@fatcity.com>


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-----
From: nlzanen1_at_ey.nl [mailto:nlzanen1_at_ey.nl] Sent: Friday, 1 September 2000 19:17
To: Multiple recipients of list ORACLE-L Subject: RE: data block waits

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 Received on Fri Sep 01 2000 - 06:47:51 CDT

Original text of this message

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