binding to cache

Hi Informix 730UC5 - Sequent Numa-Q I was discussing caching with a consultant that we have in at the moment, she mentioned that in oracle and sybase you can bind the database to cache - but this comes with the overhead of high memory usage. I was wondering if you can do a simular thing in informix. When I look at the output of an onstat -p it tells me that my read cache is at 97-99% and my write cache is at 95% - I am very happy with the read cache and the write cache seems to do the job also. So my questions are; Can I bind my informix database to cache and if so how. Or because on the onstat -p does this mean I am already bound to cache or is this dynamic caching or have I got it completely wrong? thanks Bridget

Bridget Reitsma <b.reitsma@auckland.ac.nz> wrote in message news:3826818F.731C735C@auckland.ac.nz... > Hi > > Informix 730UC5 - Sequent Numa-Q > > I was discussing caching with a consultant that we have in at the > moment, she mentioned that in oracle and sybase you can bind the > database to cache - but this comes with the overhead of high memory > usage. I was wondering if you can do a simular thing in informix. When > I look at the output of an onstat -p it tells me that my read cache is > at 97-99% and my write cache is at 95% - I am very happy with the read > cache and the write cache seems to do the job also. That's great ! You caching percentages looks perfect. Probably you don't need any improvements to your configuration. > > So my questions are; Can I bind my informix database to cache and if so > how. Or because on the onstat -p does this mean I am already bound to > cache or is this dynamic caching or have I got it completely wrong? You can set table\\index\\fragment to be resident. For details dee 'Informix Guide To SQL, Volume 2', P 2-575. ------------------------------------------------- With best regards, Yuri Dovgart SAP R/3, Informix technical consultant, Informix Certified Professional, Senior System Consultant System Architecture and High Availability Systems, 'Telecominvest' company Email y_dovgart@tci.ukrtel.net ICQ 39284285

Bridget Reitsma wrote: > > Hi > > Informix 730UC5 - Sequent Numa-Q > > I was discussing caching with a consultant that we have in at the > moment, she mentioned that in oracle and sybase you can bind the > database to cache - but this comes with the overhead of high memory > usage. I was wondering if you can do a simular thing in informix. When You can tell the engine that you would like a particular table, table fragment, index, or index fragment to be considered "RESIDENT" which means that any pages from that object that are loaded into cache are marked HIGH priority and can only be replaced by pages from some other HIGH priority object, or other pages from the same object. This improves the cache recidency of of highly active, or periodically active, objects. > I look at the output of an onstat -p it tells me that my read cache is > at 97-99% and my write cache is at 95% - I am very happy with the read > cache and the write cache seems to do the job also. Those cache percentages are superb. Whoever tuned your server did a fine job, or you just access only a very few pages (one or the other ;-) ). > So my questions are; Can I bind my informix database to cache and if so SET TABLE|INDEX name [(dbspacelist for fragments)] MEMORY_RESIDENT|NON_RESIDENT; > how. Or because on the onstat -p does this mean I am already bound to > cache or is this dynamic caching or have I got it completely wrong? It means that 99% of the time the pages your applications are looking for are already in cache, yes. They are not 'bound' in the sense that RESIDENT table pages are 'bound' but they are there non-the-less. Art S. Kagel