"control file sequential read" wait during RAC Benchmark ?

  • From: "VIVEK_SHARMA" <VIVEK_SHARMA@xxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Tue, 27 Feb 2007 18:37:07 +0530


During internal 2 Node RAC Benchmark OLTP Nature Transaction Runs,
following are the TOP Events from Statspack.

Qs 1) How can the "control file sequential read" wait be reduced after
identifying the respective "busy" Objects?

Qs 2) Should Transactions be grouped Logically so that Transactions Hit
different Data Blocks on the 2 Nodes?

Top 5 Timed Events
Avg %Total

wait   Call

Event                                            Waits    Time (s)
(ms)   Time

----------------------------------------- ------------ -----------
------ ------

CPU time                                                        12

control file sequential read                    21,969           7
0   25.4

reliable message                                    35           4
113   14.1

db file parallel write                           2,486           1
1    5.2

row cache lock                                     154           1
4    2.2


From the Manual:-

control file sequential read

Reading from the controlfile. This happens in many cases. For example,

*       making a backup of the controlfiles
*       sharing information (between instances) from the controlfile
*       reading other blocks from the controlfiles
*       reading the header block

Wait Time: The wait time is the elapsed time of the read.



The controlfile from which the session is reading. 


Block number in the controlfile from where the session starts to read.
The block size is the physical block size of the port (usually 512
bytes, some UNIX ports have 1 or 2 Kilobytes). 


The number of blocks that the session is trying to read. 



Solaris 10

Veritas CFS 5.0

Banking Product

Will Share Statspack etc with anybody


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