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. .

 

 
DB2 for z/OS and Data-as-a-Service and Database-as-a-Service______-as-a-service is all the rage in IT these days, and understandably so -- the "service-ization" of information technology capabilities and interfaces will be transformational; indeed, transformations have already occurred or are underway at many organizations and within many application develop…
DB2 for z/OS: Something You Might Not Know About Large Page Frames in a Post-DB2 10 EnvironmentI well remember the first time I saw it. August, 2016. I was looking at output from the DB2 for z/OS command -DISPLAY BUFFERPOOL(ACTIVE) DETAIL, issued on a DB2 11 system, that a client had sent to me for review. I appreciated the fact that I could see in this command output information about DB2's …
DB2 for z/OS: Running REORG to Reclaim Disk SpaceThink of why you run the DB2 for z/OS REORG utility, and a number of reasons are likely to come quickly to mind: to restore row order per a table's clustering key; to reestablish free space (for inserts and/or for updates); to remove the AREO* status set for a table space following (for example) an …
DB2 for z/OS: the PGSTEAL and PGFIX Options of -ALTER BUFFERPOOLRecently, a DB2 for z/OS professional I’ve known for some years sent to me a question about the relationship between the PGSTEAL and PGFIX options of the DB2 command -ALTER BUFFERPOOL. It took a few iterations of question and answer to get things straightened out, and I thought, “Hmm. If this pe…
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…