Once again I was asked about DSNDB01.SPT01 compression in DB2 10. Some still remember a few commits made just as DB2 10 became generally available (GA) discussing how SPT01 compression wouldn’t be needed in DB2 10. Those first comments were based on the fact the a lot of the information in SPT01 was being moved to large objects (LOBs) and LOBs cannot be compressed. If SPT01 data was being stored in LOBs and LOBs can’t be compressed, there would be no need for compression.
Have you ever wondered exactly what some of the system parameters (or DSNZPARM keywords) actually do for you (or to you)? Some are so straightforward, just looking at the keyword gives away all you need to know. However, there are some, even after research their meaning can still sometimes elude you. And that’s assuming you can even find their description (as in some DSNZPARM keywords delivered via the maintenance stream). It’s those DSNZPARM keywords I want to talk about today. Or rather, the kind I want to hear from you about today.
Today’s blog post discusses two DSNZPARM keywords (MAXCONQN and MAXCONQW on the DSN6FAC macro) that were introduced on December 13, 2012 via APAR PM43293 to improve management of (distributed) database access threads (DBATS). However, before we (that proverbial group of nonexistent people that live in my head that always tend to volunteer me for stuff that always seems to get me into trouble) get into the details of these two new system parameters, I thought it would be prudent to review a few of the existing distributed terms (like DBAT) and a few DSNZPARM keywords that are used in APAR PM43293’s cover and in today’s blog post: MAXDBAT and CONDBAT on the DSN6SYSP macro and CMTSTAT on the DSN6FAC macro.
It looks like an all DSNZPARM APAR Friday today. I have two APARs, both dealing with ZPARMs in one way or another, one is a HIPER, and both sound pretty interesting.
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 »
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 »
Back on July 11, 2011 ( I can’t believe it’s been a year almost already) I wrote about a new DSNZPARM keyword that was introduced that applied a timeout controls on DDL, different from the rest of the timeout knobs that already existed in DB2. That post along with all the details about the ZPARM can be found at “An additional timeout control is added to DB2 for z/OS” …… Continue reading »
DB2 10 has been great for my DSNZPARM presentation. There were so many new ZPARM keywords delivered with the DB2 10 base release and even more new DSNZPARM keywords showing up in APARs since general release (GA). Today, we’ll discuss one more ZPARM arriving via APAR…… Continue reading »
There is a correction in DB2 9 and DB2 10 to how DB2 automatically converts from index based partitioning to table based partitioning using the system parameter IX_TB_PART_CONV_EXCLUDE (introduced by APAR PM45829, see below). The system parameter controls whether all columns are used during the conversion or only significant columns are used. The cover contains a nice explanation that includes examples…… Continue reading »
In today’s DB2Night Show episode, I made the offer to put together a presentation based completely on the DSNZPARM keywords you all are interested in discussing. I was very serious about the offer. In fact, the more I think about it, the more I’m looking forward to putting something together…… Continue reading »