Re: parallel query wait events

hopehope_123 wrote:
> Hi Sybrand , Daniel ,
>
> Thanks for your answers. This oracle 9.2.0.5 rac with 2 nodes on redhat
> linux 2.1 ia64 and data warehouse type system.
> The disk subsystem is emc and raid 10 . (So the data is in theory
> distributed inside the emc. )
>
> Anyway , when i query the table by using sqlplus , it is very fast .
> After than , i started to check the spss part. This tool uses odbc ,
> (data direct odbc for sun - 64 bit) , after enabling the odbc trace ,
> i see for the above query and wait events , the spss process waits on
> sqlfetch odbc call. There exist a parameter called ARRAY SIZE (client
> fetch buffer size) which is 60000 by default for the odbc driver , i
> changed it to a lower value( 1000) and things has started to run fast .
> Now the client runs faster.
>
> Kind Regards,
> hope

For most things I find arraysize of 100-500 is optimal.

If you go to www.psoug.org
click on Morgan's Library
click on SQL*Plus
you will find a simple demo I use for demonstrating the importance of setting arraysize. 60000, to me, seems outrageous as a default.

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)