Re: What is a best organization for dbspaces?

> I am trying to find out what is the best plan to organize dbspaces > on online 5.x. The manual gives me some guide lines to put > rootdb,logical log and phisical log in separate devices to aviod > disk congestion and dbspaces with active tables at the center of > the device. But how do I locate a center of the device? Is there a > way to monitor the disk access times? > > Thanks in advance. > > Siva Reddy > AT&T Your goal is to maximize I/O throughput by allowing several things to happen at once. If there is only one spindle for rootdb, logs, and data then an update may have to wait for each of these functions to complete on the one disk, one after another. It can be important to use separate controllers as well as disk drives, otherwise the bottle- neck remains "at the disk". I pretty much ignore the "center of the disk" thing. IMHO that's like the old adage that you'll get better gas mileage by washing your car. Maybe that's theoretically true, but it doesn't make any real difference and you can spend your time better (get a greater return on your time investment in terms of application speed) by analyzing the application itself than by worrying about the difference in access time from the center to the edge of the disk. Besides, that's just another thing to keep up with, and you've got more than enough just juggling those partitions and offsets already. Joe Lumbley advises using the "tbstat -D" command with the "tbstat -z" to reset and monitor the disk access rates. (You should have a copy of his book anyway). Do this during a large transaction to gauge responsiveness. Note that this exercises the whole system, and does not just measure disk access time. (Read the advertising to get the various vendor's access times. :) ) That's some of the theory, anyway. With prolixity, __________________________________________________________________ | Clem Akins Standard Disclaimers Apply | |Reynolds Metals Co, Alloys Plant "Climb High, Cave Deep!" | | Muscle Shoals, Alabama USA cwakins@leia.alloys.rmc.com | |________________________________________________________________|