Re: 7.20 performance.

erik@rat.se (Erik Heimdahl) wrote: >I have recently upgraded to 7.20.UC2 from 5.07.UC1 on my SPARC 20 (single processor) running >SOLARIS 2.5.1, and the first performance-tests I made is really bothering me. >When doing very simple tasks as pure INSERTS, UPDATES and SELECTS from indexed tables i get a >better performance from my 5.07 than from the 7.20. >In some SPL run through DBACCESS i get about 30% better juice from 5.07. >Doing the same operations in ESQL/C takes about twice the amount of time in 5.07, which is >acceptable concerning the flow of data between the sqlturbo-process and the ESQL/C program. >The same operations using ESQL/C-7.20 takes about six(6) times longer than using SPL-7.20, which >still is slower than 5.07. >All in all, ESQL/C seems to be more than twice as fast on 5.07 than on 7.20, and pure raw >performance about 30 % better. >The OS is configured according to the parameters in /usr/informix/release and when using onperf >and dbcockpit, I can't see anything else than what You might expect. >Has anyone experienced something like it ?? >Is this a known problem, or have I not been able to configure 7.20 correctly (there are not that >many parameters to fiddle with on a simple application like this) ?? Erik, I think this is a common result that a lot of people see when they migrate a very simple application to the DSA architecture(6.x & up) from 5.x. The DSA engines were designed to perform best on multiprocessors systems(at least 2 or more). That's not to say that DSA can't work or performs poorly on all single processor systems. However, you do have to pay close attention to how you have your config parameters set in releases such 7.2. Look at your onstat -p output or run some of the onstat -g commands to see if they show what may be causing slower performance. How much memory do you have on your Sparc 20? Remember, DSA consumes a lot more of shared memory than did 5.x. Are you using cooked devices or the suggested raw devices.? Do you have root dbspace, logical and physical logging on different disks? Just a few things to check, but bottom line is that depending on your application and your hardware, you may or may not see an improvement in performance going from 5.x to 7.x. HTH -- Melvin Mariney, Informix DBA e-mail: melvin.mariney2@bridge.bellsouth.com