November 29, 2016
I recently attended a regional DB2 user group meeting, and the subject of continuous delivery
came up frequently. People were wondering about the process of adding new features being added through the maintenance stream and how to fallback if it's determined that the new features are causing a problem.
As it happens, the IBM Knowledge Center
has new documentation about continuous delivery and DB2 12 function levels:
New DB2 capabilities and enhancements are continuously delivered in a single maintenance stream as the code becomes ready. You can activate the new capabilities in a data sharing group or DB2 subsystem after a function level is delivered. A function level corresponds to a single PTF that enables a specific set of enhancements that have shipped in previous PTFs.
The above link directs you to a list of available DB2 12 function levels, so by all means, read the whole thing.
I believe any DB2 systems programmer responsible for maintenance, installs and migrations will love continuous delivery. Now instead of having to undertake lengthy upgrade projects, you'll simply apply maintenance just as you always have -- but on an ongoing basis.
Prior to DB2 12 you may have applied a PTF or an RSU to fix something. Without even realizing it, though that process you were also adding new features to DB2. The difference with DB2 12 is that IBM is now documenting when new features become available by function level. So DB2 pros can control when these new features become active and when applications can start using them.
DB2 11 introduced application compatibility, which allows you to determine the version of DB2 code that SQL statements execute under. This allows DB2 sysprogs to take advantage of new system level performance features without having to upgrade the application. It also removes the "big bang" approach, in that you don’t have to test all your different applications and get them all to agree before activating new features.
In DB2 11, the application available parameter settings are either V11R1 or V10R1. Starting with DB2 12, new functionality will be introduced during the maintenance stream, and the settings will be V12R1M### (where ### is the function level).
To activate a given level of new functionality, invoke the ACTIVATE FUNCTION LEVEL command. Once the system is running with a given function level, the applications can take advantage of the new capabilities once the application compatibility parameter is set to the new function level. (Note: With DB2 12 the application SQL statement can continue to run with DB2 10 or 11 expected behavior using V11R1 or V10R1.)
Once you migrate to DB2 12, you'll have the following function levels:
- V12R1M100 : Identifies compatibility with the function level before you activate new function, after migration to DB2 12, function level 100. V12R1M100 is the same as V11R1.
- V12R1M500: Identifies compatibility with the function level that enables new function in the initial DB2 12 release, function level 500. V12R1M500 is the same as V12R1
- V11R1: Specifies DB2 11 compatibility behavior. V11R1 must not be specified in the body of a trigger.
- V10R1: Specifies DB2 10 compatibility behavior. V10R1 must not be specified in the body of a trigger.
For more, see the SQL Reference Guide
or visit the IBM Knowledge Center
Making it possible for customers to rapidly put new features into production through normal maintenance is huge for the mainframe's continued viability. Businesses will now have a more positive view of running applications on DB2 for z/OS because they know they'll no longer have to wait years for required features.
Posted November 29, 2016 | Permalink