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. .

 

 
Clearing the Air Regarding Db2 12 for z/OS and "Deprecated Objects"On a number of occasions over the past several months, I have seen that there is some misunderstanding in the Db2 for z/OS community regarding support for certain types of database objects in a Db2 12 environment. Via this blog entry, I want to clear up these misconceptions. The misunderstandings t…
Db2 for z/OS Online LOAD REPLACE - Minimizing Impact on TransactionsA couple of years ago, IBM introduced an important enhancement for the Db2 for z/OS LOAD utility, via the fix for an APAR (the APARs are PI69095 for Db2 12, and PI67793 for Db2 11). This enhancement provided a capability that is popularly known as "online LOAD REPLACE," but is more formally referred…
Db2 for z/OS: Clearing Up Some Matters Pertaining to 10-Byte RBA and LRSN ValuesAt this time, many Db2 for z/OS-using organizations have already completed their migration to Db2 12. Others are still in the process of accomplishing that migration, or are finalizing migration plans. Especially at sites at which migration to Db2 12 is not yet a fait accompli, I have seen that ther…
Db2 for z/OS and RACF, Part 2: Db2-Internal SecurityIn the Part 1 post of this two-part blog entry, I described how RACF can be used to provide "external" security for a Db2 for z/OS system - external security being concerned with who (i.e., which IDs) can connect to the Db2 system, and how (e.g., in the form of a batch program and/or through CICS an…
Db2 for z/OS and RACF, Part 1: External Db2 Security In a Db2 for z/OS context, RACF (the IBM security management subsystem for z/OS systems) can serve two important purposes, providing security for a Db2 environment in an external and an internal sense. Db2 external security is about determining which users/processes can connect to a Db2 subsystem, a…
Clearing Some Things Up Regarding the CICS-Db2 for z/OS InterfaceNot long ago, a very experienced Db2 for z/OS person contacted me with some questions about the CICS-Db2 interface. He mentioned that he did this because he was having trouble finding the information he was seeking in the product documentation. I provided this person with answers to his questions, a…
Db2 for z/OS: The Potential Performance Impact of 100% CPU UtilizationTwice during the current calendar year, I've worked on a Db2 for z/OS performance issue that I've encountered at various times over the past couple of decades: a transactional Db2 for z/OS workload (versus batch - more on that in a moment) has periods characterized by major increases in response tim…
Db2 12 for z/OS - Let's Talk About MAXDBAT in ZPARM"ZPARMs" is a reference to the parameters in the Db2 for z/OS module called DSNZPARM - these are essentially the configuration parameters for a Db2 subsystem. Two of the ZPARMs that are closely related to each other are CONDBAT and MAXDBAT. CONDBAT specifies the maximum number of connections that ne…
The Two Aspects of Db2 for z/OS Support for JSON DataJSON (JavaScript Object Notation) is a form of data representation that is popular with people who develop what you might call "very modern" applications, including those that are cloud-based and those that have a mobile front-end. One reason this is so: a JSON document is easy for a program (or a p…
Db2 for z/OS - Talking About APPLCOMPAT (Part 2)Last month, I posted to this blog part 1 of a 2-part entry on the APPLCOMPAT option of the Db2 for z/OS BIND PACKAGE command. In that entry I covered several aspects of APPLCOMPAT. In this part 2 piece, I will focus on one particular matter pertaining to APPLCOMPAT - namely, the management of this o…