Author Archives: Martin Packer

(Originally posted 2006-04-20.) Here’s my first tip with the new UK90006 / UK90007 DFSORT PTFs. It’s an apparently minor enhancement that I think people will like… It leads to a more elegant syntactical expression. It is more maintainable – in the face of changing record layouts. Suppose you want to search a file for aContinue reading “Search and Replace with the new DFSORT functional PTFs”

(Originally posted 2006-04-20.) As many of you know I like to beta DFSORT function PTFs. About once a year a new set of functions appears, many in direct response to customer requirements. Occasionally some of the enhancements are at my suggestion. 🙂 Yesterday PTFs UK90006 and UK90007 became available. (Being UK based it’s nice toContinue reading “DFSORT New Function PTFs”

(Originally posted 2006-04-07.) As of today I have a new job. I still work for IBM. I’m still UK based. I still do performance analysis with customers in the same way. But some things have changed: I now work in Software Group, rather than what’s now called Global Technology Services. I now have a geographicalContinue reading “My New Job”

(Originally posted 2006-04-06.) I’m strongly considering writing a DB2 Data Sharing For Beginners presentation. In fact I have a proposal in to do just such a thing for the US z/OS Conference (in Orlando in October). Obviously that would be a presentation I’d like to take to eg UKCMG and the EMEA z/OS Conference nextContinue reading “DB2 Data Sharing Performance for Beginners”

(Originally posted 2006-04-03.) In this entry I talked about an APAR that fixed an issue with mixed farms of control units, where only some supported MIDAWs. Here’s another APAR. This one could increase the performance benefit of MIDAWs. APAR OA15556 changes the way IDAWs (Indirect Data Access Words) are placed in memory, relative to theContinue reading “Another MIDAWs APAR – Might Improve Its Performance”

(Originally posted 2006-03-30.) Long ago the DB2 REORG utility traded memory for speed with SORTKEYS and SORTDATA. The latter caused the object being REORGed to be unloaded and externally sorted (eg using DFSORT). (SORTKEYS was similar but for the keys to REORG the indexes.) This is fine if you have the memory to drive eitherContinue reading “More REORG Utility Flexibility”

(Originally posted 2006-03-30.) Just briefly, here are some Access Path fixes I’ve been meaning to talk about: PK14923 QUERY COST ESTIMATE IS TOO HIGH IN SOME CASES PK16521 ONE FETCH INDEX ACCESS (I1) NOT USED WITH DUPLICATE PREDICATES PK15143 POOR QUERY PERFORMANCE WHEN SORT MERGE JOIN IS CHOSEN AND MULTIPLE JOIN COLUMNS ARE POSSIBLE ORContinue reading “Some SQL Access Path Improvements”

(Originally posted 2006-03-30.) One of the themes for Distributed access to DB2 that I talk about is Network Flows Optimisation, in particular ensuring that DB2 is taking advantage of such things as blocking… When DB2 sends rows back to a DDF caller it can block them or return them singly (and indeed the degree ofContinue reading “DDF Row Counts Bug”

(Originally posted 2006-03-30.) I present at conferences on what I call New World DB2 application performance, by which I mean such things as Stored Procedures, SAP R/3 and BW, Distributed (DDF) and JDBC. I do this because I think us mainframe performance people need to lead conversations on DB2 application performance that actually acknowledge whatContinue reading “DB2 As A Web Services Provider”

(Originally posted 2006-03-10.) A little off-topic, perhaps, but I’ve just installed the second Alpha of Lotus Sametime 7.5, IBM’s recently-previewed new instant messaging client. I would’ve liked to have installed the first Alpha but I’ve been working hard on behalf of one of my favourite clients until yesterday. There’s that phrase again, Brian. 🙂 Actually,Continue reading “Lotus Sametime 7.5 Alpha 2”