Re: back-end growth

In article <1992Oct11.2231.1801@execnet>, clay.irving@execnet.com (clay irving) writes: > On 10-11-92 Ihor J Kinal writes: [ That's me] > > |Recently, I posted an article about the backend [sqlturbos] > |growing in Online 4.10 UE1 and UE3P1. > | > |Further investigation showed one specific case to be where > |we had a cursor that had been prepared once [the specific > |query was a join between two tables]. After about 50 open/closes, > |we discovered steady growth in our backends. > > Maybe this explains what's been happening to my system. I'm running 4.10 > UE1 on an IBM RS/6000. I have a batch 4GL program that I tried to run > against 37,000 rows. I have 16MB of memory with 32MB page space. Everytime > I run the program it ABENDs -- Not enough memory. I watched sqlturbo go > from 1MB to 2MB to 3MB... to 8MB.. Eventually it eats all the virtual > memory and the RS/6000's Virtual Memory Manager starts killing processes. This sounds like a different problem than what we've seen. Try to reproduce the problem with the simplest number of statements, and then post the program, or forward it to Informix support. NOTE that we're STILL seeing significant growth in backends, and some growth in our FRONT-ends. Our colleagues, running a SIMILAR system on Online 5.0, are seeing phenominal growth in front-ends ONLY. Although we no longer have our TURBO systems available, we think that these problems were NOT as apparent under turbo. APPARENTLY [and we're still testing the results], the growth can be checked, by consistent use of $free'ing prepared statements that are no longer needed, and possibly freeing cursors after they're closed as well. [Note that in 5.0, you can IMMEDIATELY free the prepared statement after you declare the cursors. This makes the logic a lot simpler. Freeing cursors does not seem work in 4.1, although you can prepare/execute a statement to do so -but don't forget to free the prepare'd statement]. THIS IS A REAL DISADVANTAGE TO ONLINE. Although free was apparently available in turbo, it was not documented there. Checking OnLine documentation, there is a brief mention of the possibility that resources will be used, and that free can be used. We're forced to minor revisions to MASSIVE amounts of code. Not fun. Needless to say, I'm not a happy camper. Standard disclaimers apply - and I hope this helps others. Ihor Kinal att!cbnewsh!ijk [netnews] att!trumpet!ijk [real work address].