We have a canned package that we use to insert approx 100 records/second
into one table (oltp environment).
Each record is just under 1K (datatypes = number and varchar).
There are several indexes that are build on the table as the records are
inserted.
Each  and every record is committed.
Therefore we are flushing the 'redo log buffer' to disk (online redo
logfiles) 100 times per second (once per commit).

Not surprisingly we have noticed IO waits which we believe are associated
with our 'Redo Log buffer'.  Namely ;
   log_file_sync = 180 waits/sec
   log_file_parallel_write = 180 waits/sec

We tried resizing the 'redo log buffer' from 16K to 256K - but we did not
notice any improvements.
Neither Log switching or archiving  seem to be excessive.
100 records per second seems to be our maximum speed without the application
queuing up and Oracle showing very high waits on log_file_sync and
log_file_parallel_writes.

Does anyone know how we might be able to minimize the IO waits?

Thanks in advance.

ENVIRONMENT
oracle : Oracle 8.1.7.4
os     : Sun Sparc Solaris 8
box    : 8x8 E10K
IO     : Hitachi SANS unit through fiber and Brocade switch


_________________________ 
 Patrick J. Howe 
  


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