btr

How can the BTR be 334 while the %cached for reads is 91% to 95% ? (This is ids11.70.TC3IE )

And that's why I developed BTR in the first place. The cache %s are not sufficient. Write cache % is just an indication of the number of times a page was written to once it was read into memory. If your records are large, write cache will be low. If they are small, write cache will be high. Read cache % tells us the x% of reads were satisfied from cache, but if 99% of all reads are hitting a a very small number of pages while the remaining reads are all reading pages that are not in memory, you get a 99% cache hit % while still suffering from IO bottlenecks which could be solved by adding more cache. Watch onstat -P over time to see what partnums are moving in and out of cache by watching which page counts go up and down between runs and by how much to determine how much cache to add to eliminate the thrashing. Art Art S. Kagel Advanced DataTools (www.advancedatatools.com) Blog: http://informix-myview.blogspot.com/ Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Advanced DataTools, the IIUG, nor any other organization with which I am associated either explicitly, implicitly, or by inference. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Wed, Sep 26, 2012 at 7:47 PM, Bill Hamilton <garage_dba@verizon.net>wrote: > How can the BTR be 334 while the %cached for reads is 91% to 95% ? > > (This is ids11.70.TC3IE ) > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --e89a8f838a5561a37404caa69825