If you haven’t, you really should. It’s changed considerably over the years becoming quite the analytics tool. However, rather than me explaining what makes QMF interesting today, how about hearing it from someone who lives QMF……. Continue reading »
Title says it all. Without this APAR, DB2 can spend a tremendous amount of time searching index space maps for free space an an effort to avoid extending the page set.
After applying this APAR, DB2 will use page list prefetch to improve search processing…….. Continue reading »
Back on January 26, 2012 I published a blog entry titled “Be careful how you define your partition-by-growth universal table space”. It discussed how once you set the MAXPARTITIONS value for a partition-by-growth universal table space, you could increase it but you could never lower it. So for example, if MAXPARTITIONS was set to 200 you could increase it to 250 however, you could NOT lower it to a lower value, let’s say 150. Lowering MAXPARTITIONS to value lower than 200 caused a –644…… Continue reading »
This one has actually been floating around now for about a week… forgot to mention it last week.. should have… and it’s excellent.
The Redpaper is written by Jeff Berger, part of the DB2 for z/OS performance team at IBM Silicon Valley Laboratory. This is someone know his stuff when it comes to getting data off disk and into your application. And this Redpaper isn’t just List Prefetch, there’s also lots about the disk subsystem…… Continue reading »
Little rhyming things and word matches in a blog’s subject is so cute… APAR Friday, Training Tuesday, Weird Wednesday, are just a few… actually Training Tuesday has it’s debut today. I wanted a fixed subject I could search on that discusses all things that help you better deal with DB2 for z/OS.. webinars, Redbooks, new publications, white papers, etc….. Continue reading »
I wanted to talk about the DSNZPARM keys deprecated in DB2 10. And yes I do realize that I listed them out in a previous post. However, this time I wanted to discuss why it’s important today, maybe even before migrating to DB2 10, to plan on how their eventual departure from DB2 may affect you.
Then someone pointed out to me that sometimes when we say something is “deprecated” in a future release of DB2, it can sometimes get misinterpreted, or misunderstood. In fact, there has been extra verbiage added to the DB2 10 Installation and Migration Guide (GC19-2974) to help alleviate future misunderstandings…… Continue reading »
For all of you that love to do performance and tuning of you DB2 subsystems, DB2 land is about to make your job a whole lot easier in the stored procedure and user-defined function (UDF) categories by improving some of the existing metrics and adding a few new ones.
The issue; a couple of numbers all lumped in together. The solution; more granularity, possibly right down to the individual stored procedure or UDF level, if everything gets set up correctly…… Continue reading »
Well over a year ago (Feb 2011) I blogged about the addition of the PARALLEL keyword that was made available on the REORG TABLESPACE LIST utility control statement. (See “APAR Friday: Another great REORG enhancement” )
As a result of the group of fixes mentioned in the above blog post, a single execution of REORG happens with a list of partitions. It does happen in parallel; that’s good news. However, sometimes, someone may want to still run the list of partitions serially… one partition at a time……. Continue reading »
The 2012 Information on Demand (IOD) conference is only 5 months away… (where has this year gone already)…. It’s being help once again in Las Vegas at the Mandalay Bay on October 21-25. Last years conference was huge. This years should be even better.
If you are a DB2 for z/OS DBA, System Programmer, or Application Programmer, you now have a new resource to add to your list of places to discover information.
The DB2 for z/OS Exchange will have much of what you need, being refreshed as frequently as each month… Were you wondering about a HIPER you heard about, or an APAR that seems like it could solve an issue you’re having? The DB2 for z/OS Exchange could be the place to find the answer….. Continue reading »