Online Performance Tuning

I would like to get a better handle on Online Performance tuning. We are running 7.3. We have a copy of "Informix-Online Performance Tuning" by Elizabeth Suto the first edition. I noticed that the second edition is available, but was published in 1996. Is there enough new information in the 2nd edition to make it worth while? I am looking at ordering "Informix Unleashed" and Joe Lumbley's new book. To recommend any others? Thanks ahead of time :-)) (Our checkpoints are running from 4 to 9 seconds; it would be nice to get that down to 2-4 seconds) Dave McNight Bob Jones University Unix/Informix Administrator

In article <36B06F8A.357@bju.edu>, dmcnight@bju.edu (Dave McNight) wrote: > I would like to get a better handle on Online Performance tuning. We > are running 7.3. We have a copy of "Informix-Online Performance Tuning" > by Elizabeth Suto the first edition. I noticed that the second edition > is available, but was published in 1996. Is there enough new information > in the 2nd edition to make it worth while? I am looking at ordering > "Informix Unleashed" and Joe Lumbley's new book. To recommend any > others? Thanks ahead of time :-)) (Our checkpoints are running from 4 > to 9 seconds; it would be nice to get that down to 2-4 seconds) > > Dave McNight > Bob Jones University > Unix/Informix Administrator > Are you running on RAID or pure raw disk? Some RAID architectures can really slow down writes, especially RAID 5. If raw disk, are you using all available disks and balancing the load across them? (Use onstat -D to check). Have you tuned the AIO VPs and the number of page cleaners? A good rule of thumb is: no. of disks = no. of chunks = no. of page cleaners. However if you have more than one chunk on the same disk and multiple page cleaners then there is the possibility that two page cleaners could be competing to write to the same disk, causing the heads to thrash between the two chunks. -Andy-