Articles & Content

Robert Catterall

Robert Catterall is a well-known DB2 z/OS expert. He is a regular speaker at IDUG events and a Past President of IDUG

Note: The content of this blog is the opinion and thoughts of the blogger and does not necessarily represent the opinions of IDUG and should not be construed as reflecting official positions of the IBM Corporation. .

 

 
Are You Using System Profile Monitoring to Manage Your DB2 for z/OS DDF Workload? Perhaps You ShouldHere's a scenario that might sound familiar to you: you have a particular transaction, which I'll call TRNX, that is the source of quite a lot of deadlock activity in a DB2 for z/OS system. It seems that whenever more than one instance of TRNX is executing at the same time, a deadlock situation is h…
In Praise of the Invisible DB2 for z/OS SystemI've been working with DB2 for z/OS -- as an IBMer, as a user, as an independent consultant -- for 30 years. I was with IBM when DB2 was introduced to the market. I've met people who were part of the core team at IBM that invented relational database technology. I was privileged to serve for a year …
DB2 for z/OS ZPARMs that Organizations Consistently Set in a Sub-Optimal Fashion Over the past several years, I have reviewed DB2 for z/OS systems running at quite a few client sites. Part of the analysis work I do in performing these reviews involves looking over a DB2 subsystem's DSNZPARM values (or ZPARMs, for short -- the parameters through which the set-up of a DB2 system i…
How Should Your Network-Attached Applications Access DB2 for z/OS?Some relatively recent developments have plenty of people asking, "How should my applications that connect to a z/OS server via a network link access DB2 for z/OS data?" In writing today I hope to provide some information that will be useful to folks pondering this question. I'll organize my thought…
DB2 for z/OS: Using PGFIX(YES) Buffer Pools? Don't Forget About Large Page FramesNot long ago, I was reviewing an organization's production DB2 for z/OS environment, and I saw something I very much like to see: a REALLY BIG buffer pool configuration. In fact, it was the biggest buffer pool configuration I'd ever seen for a single DB2 subsystem: 162 GB (that's the combined size o…
DB2 for z/OS: Clearing Up Some Matters Pertaining to Database Access ThreadsI have recently received a number of questions pertaining to DB2 for z/OS database access threads, or DBATs. DBATs are threads used in the execution of SQL statements that are sent to DB2 from network-attached applications (i.e., from DRDA requesters that access DB2 for z/OS by way of DB2's distribu…
DB2 for z/OS: Clearing the Air Regarding CLOSE YES for Table Spaces and IndexesThis is another of my DB2 for z/OS blog entries motivated by a desire to clear up a matter about which there is some misunderstanding in the DB2 community. In this case, the misunderstanding concerns the CLOSE option of the CREATE and ALTER statements for DB2 for z/OS table spaces and indexes. The …
DB2 for z/OS: Indexes and Foreign KeysThe functionality of DB2 for z/OS is enhanced, in ways small and big, on a regular basis. There's plenty to keep up with, and it is understandable that some product improvements could fly under the radar of a database administrator and escape notice. I encountered this situation a few weeks ago. Dur…
DB2 for z/OS: When Did You Last Check Your Checkpoint Frequency?I have written in this blog a few entries about various DB2 for z/OS ZPARM parameters, including a post on DSMAX and another on EDM_SKELETON_POOL. Time for another such entry, this time focused on the parameters that determine when a DB2 subsystem will perform checkpoint processing. Checkpointing i…
DB2 for z/OS: Should You Do Some Buffer Pool Consolidation? 19, 19, 23, 26. Know what these numbers have in common? They indicate the number of 4K buffer pools allocated for four different production DB2 for z/OS subsystems that I analyzed over the past couple of years. I believe that there are quite a few sites where a plethora of 4K buffer pools have been…