Author Archives: Martin Packer

(Originally posted 2007-02-18.) Whatever one’s feelings about the definitiveness of Wikipedia a lot of people find themselves there, looking for information. Having twice anonymously edited articles – in one case to correct an error, in the other to add a minor snippet – I finally succumbed to the urge to get an ID. So myContinue reading “Wikipedia”

(Originally posted 2007-02-08.) Willie Favero is also blogging about this – and I stole the link from him… Here’s the End of Service announcement for DB2 Version 7. It goes out of service on June 30, 2008. I’ve just sat through four days of the T3 class for DB2 9 for z/OS – in SiliconContinue reading “DB2 9 and End Of Service For DB2 Version 7”

(Originally posted 2007-02-08.) See the z/OS Release 9 preview statement if you’re interested in z/OS. There are lots of interesting Performance items previewed, as well as other line items. It’s expected to become available in September 2007, following the current pattern of a new release each year (preview in the so-called Spring :-)and release inContinue reading “z/OS Release 9 is Previewed”

(Originally posted 2007-01-31.) I suggested (in z/OS Release 8 Real Storage Manager SMF Record Changes) that I might talk about the changes to RSM in z/OS Release 8. As the release has been out now for about 4 months some of you might actually be on the brink of putting it into production. 🙂 Seriously,Continue reading “z/OS Release 8 Real Storage Changes”

(Originally posted 2007-01-26.) I presented to the Large Systems GSE meeting in Dudley on Wednesday on “DB2 Data Sharing Performance For Beginners” and an interesting question came up… “At what distance does performance begin to suffer when moving machines in a parallel sysplex apart?” As it happens I am dealing with exactly that question inContinue reading “Going The Distance”

(Originally posted 2006-12-13.) I’ve just been looking at some fascinating SMF 70 records. They come from a System z9 EC S54 machine and the LPAR they’re from is running z/OS Release 8. I say “fascinating” because: I’ve not seen an S54’s data before. (This is the largest z9 machine – with all 4 processor booksContinue reading “z/OS Release 8 CPU SMF Record Changes”

(Originally posted 2006-11-30.) In z/OS Release 8 Real Storage Manager (RSM) implemented brand new algorithms. One of the more significant changes was the adoption of a “new style” UIC value. This behaves much more like the old Expanded Storage Migration Age. Accordingly the old UIC value (SMF71ACA) isn’t really appropriate to use anymore. Or atContinue reading “z/OS Release 8 Real Storage Manager SMF Record Changes”

(Originally posted 2006-11-22.) In Mainframe v-Business Boas Betzler threw out a challenge: “Demonstrate SecondLife talking to CICS”. I’ve picked this up on behalf of IBM. Now, why on earth would you want to do that, Martin? To get beyond the “because it’s fun” answer (which is also true) let me tell you my view onContinue reading “CICS and SecondLife”

(Originally posted 2006-11-08.) Well, I don’t know about that. Maybe this contribution to the debate won’t add much. But there must be at least one performance person out there who hasn’t heard of the discussion around RMPTTOM. But would I want such a person amongst my readership? 🙂 I’m not going to rehearse the wholeContinue reading “Better Late Then Never – RMPTTOM”

(Originally posted 2006-05-22.) Here are a couple more SQL processing APARs. APAR PK22814 for Version 8 ESTIMATED SUBQUERY COST IS TOO HIGH WITH SORT MERGE JOIN. The APAR text says Correlated subquery cost is over-estimated for sort merge join. A well-performing sort merge join plan might not be chosen by DB2. Correlated subquery cost canContinue reading “2 More DB2 Access Path APARS”