A World of Functionality Delivered in Db2 13 for z/OS

Db2 12 for z/OS has been available now for close to 7 years, which is a “forever” in the world of enterprise software. But more than a year ago now IBM delivered a brand new release of Db2, Version 13! Db2 13 for z/OS was announced on April 5, 2022 and was delivered for general availability on May 21, 2022.

This came as welcome news to many Db2 users as the six years between V12 and V13 was the longest ever between new releases of mainframe Db2. But this was by design, as IBM adopted a continuous delivery strategy for Db2 as of V12.

Under IBM’s continuous delivery model, new features, enhancements, and fixes are delivered to customers on a regular basis, instead of waiting for a new release or version. This approach allows customers to receive updates and improvements to the Db2 software without going through a traditional major release upgrade process.

With Db2 continuous delivery, IBM delivers new features and enhancements as “function levels,” or FLs. Each FL represents a set of new capabilities and improvements that customers can choose to adopt. This model enables customers to take advantage of new features and enhancements more quickly and easily than with a traditional version upgrade, as the FLs are delivered via the regular software maintenance process.

The continuous delivery model allows organizations to adopt new features and enhancements at their own pace, based on their specific needs and requirements. It provides a more incremental and agile approach to software updates, allowing customers to stay current with the latest features and improvements while minimizing disruption and reducing the complexity associated with traditional major release upgrades.

IBM delivered 10 Db2 function levels during the lifespan of Db2 12 for z/OS before releasing Db2 13 for z/OS. All of this is a build up to the new Db2 13 for z/OS release.

Starting at the Beginning…

What do you need to know about Db2 13 for z/OS? Well, let’s start at the beginning. The first thing most shops will need to do is activate Db2 12 function level 510 (FL510) before they can migrate to Db2 13. 

Unlike all the other function levels, FL510 does not add any new features or capabilities, nor does it introduce any new changes to the Db2 Catalog. So, what does it do? FL510 is basically there to prepare for the new release of Db2. You can think of it as housekeeping and tidying up to prep for Db2 13. When you activate FL510 it verifies and enforces pre-migration conditions that have to be met before you can migrate to Db2 13, such as ensuring that all Db2 12 function levels are activated and that all catalog updates for Db2 12 have been applied. Additionally, FL510 will check to make sure that your application packages were rebound recently enough to ensure that they are supported by Db2 13. If any of the previous conditions are not met, then the activation of FL510 will fail. You will have to remediate your system and try to activate FL510 again before you can move forward to the new version.

The bottom line is that FL510 is a boring function level in that it delivers no new functionality… but it is required before you can migrate to Db2 13. The interesting part will be watching how this impacts customer migration. Many organizations are lagging behind in terms of function level activation, so it may take some time before they make their way to FL510 before they can start their migration to Db2 13.

Db2 13 for z/OS Function Levels

Seeing as how we are now more than a year into the lifecycle of Db2 13 for z/OS, it is important to note that there have been two new FLs delivered for this new version since general availability. FL502 was delivered in October 2022 and FL503 was delivered in February 2023.

Function level 502 introduces Db2 controlled Sysplex workload balancing and adds infrastructure for statement-level invalidation. Function level 503 introduces improved default behavior for added ROW CHANGE TIMESTAMP columns in existing rows, accelerator-only support for queries with IN list predicates with more than 32K elements with IBM Db2 Analytics Accelerator V7 for z/OS, and optimize-clause support for SELECT INTO statements.

According to information provided by IBM, the regular schedule for Function levels on-going is 2 per year, with one in the spring and another in the fall. Although past FLs have not always been delivered exactly on that schedule, this is the cadence that you should expect and plan for into the future.

You may also have noticed that the first new function level for Db2 13 for z/OS is FL502, and not FL501 like it was for Db2 12. This is because the upgrade sequence has changed for Db2 13. The following is the sequence for moving from Db2 12 to Db2 13 for z/OS:

  • You must first have activated Db2 12 FL510 to validate the readiness of you Db3 environment to be upgraded to Db2 13 for z/OS
  • When you move to Db2 13 FL100 there is no new external functionality. There is a trivial CATMAINT required at this point.
  • At Db2 13 FL500 all new features that do not catalog changes are supported.
  • And finally, Db2 13 FL501 supports all the “initial” new features of Db2 13. By “initial” I mean those that do not require a subsequent, higher FL.

New Functionality in the Base of Db2 13 for z/OS

OK, so far, so good, but what about the new functionality in Db2 13? The first thing to take note of is the on-going synergy between Db2 and IBM Z. Many DBMS products are designed to be heterogeneous; that is, to function across multiple operating systems with little or no changes required. But Db2 for z/OS is engineered specifically for the IBM Z mainframe and can therefore take advantage of unique aspects of the hardware.

One example of this synergy is the exploitation of the IBM Integrated Accelerator for Z Sort, and its SORT LISTS (SORTL) machine instruction, available on IBM z15 and later models. This can greatly improve the efficiency of sorting Db2 data.

Another example of zSynergy is the ability to take advantage of more concurrent data sets and threads, as delivered by z/OS 2.5. The maximum number of open data sets in Db2 13, as controlled by the DSNZPARM DSMAX, has been doubled, from 200,000 to 400,000.

Additionally, the IBM z16 System Recovery Boost can minimize downtime by speeding up the performance of Db2 for z/OS restart.

Next time, we’ll look at AI and Db2 in Db2v13.

Regular Planet Mainframe Blog Contributor
Craig Mullins is President & Principal Consultant of Mullins Consulting, Inc., and the publisher/editor of The Database Site. Craig also writes for many popular IT and database journals and web sites, and is a frequent speaker on database issues at IT conferences. He has been named by IBM as a Gold Consultant and an Information Champion. He was recently named one of the Top 200 Thought Leaders in Big Data & Analytics by AnalyticsWeek magazine.

Leave a Reply

Your email address will not be published. Required fields are marked *