Re: Detaching Indexes

>To spread the workload on our drives, we have taken the approach of >detaching the index from our tables. Our indexes are on one set of >disks and the data is stored on another set of disks (ie, physically >separate disks). > >If some cases we have seen comparable results when the indexes are >attached vs. indexes not attached. Lately, we have seen our performance >begin degrade. The only things to change in our environment is the >amount of data has increased and initializing the instance in using >Shared Mem as opposed to TLITCP. > >Any thoughts on the +'s or -'s of distributing data in this way? > >PS. We are running on Solaris 2.5.1 and ODS 7.23UC1. >-- Steve, This will help *if* your degredation is caused by IO bottle-necks. Generally speaking, striping the data portions will improve performance even better. However, before any change is made to improve performance, careful analysis needs to be done to the existing configuration to ensure that you have discovered the "real" bottleneck that you are encountering. Check your onstat -p. What is the read cache rate? - hopefully above 98%. Do the sar -A and iostat reports indicate there is an large imbalance in the IO distribution patterns. Are you seeing "wio" times? Are you seeing "po" numbers and/or swapping? Basically, before any change is made to improve performance on you system, make sure that you've carefully (and objectivly) analyzed the existing environment. Moving data arround takes a lot of (down) time and you really want to make sure that you will be getting the desired results before you start. Madison Pruet