Of course, this impacts DBAs and systems programmers who manage the version of Db2 more than it impacts developers. That said, developers always need to be aware of which version and now, level, of Db2 that they are using. This is important because it dictates the features that are available to use.
As part of the continuous delivery of Db2 functionality, Db2 12 adds several built-in global variables to help. In actuality, these new variables can be read by any application in Db2 11 NFM and Db2 12 (as long as the Db2 11 subsystem has applied the Db2 12 migration SPE and executed CATMAINT).
The first global variable we will discuss is PRODUCTID_EXT, which stores the extended product identifier of the database manager that was used to invoke the function. The value is VARCHAR(30) and it is maintained by the system. The schema is SYSIBM.
The format of the extended product identifier values is pppvvrrmmm, defined as follows:
- ppp is a three-letter product code (such as, DSN for Db2)
- vv is the version
- rr is the release
- mmm is the modification level (such as, 100, 500, 501)
For example, DSN1201501 identifies Db2 12 after the activation of Db2 12 new function level 501. Function level 500 is the first Db2 12 function level so any level 500 or greater indicates Db2 12 new functionality is availabile.
An application accessing PRODUCTID_EXT from a coexistent Db2 11 member of a data sharing group would see a value of DSN1101500.
The second new global variable for continuous delivery is the CATALOG_LEVEL. Appropriately enough, this global variable contains the current catalog level. Again, the data type is VARCHAR(30) and it is maintained by the system with a schema of SYSIBM.
The format of the catalog level values is VvvRrMmmm, defined as follows:
- vv is the version
- r is the release
- mmm is the modification level (such as 100, 500, 501)
For example, V12R1M500 identifies Db2 12 after the activation of Db2 12 and the initial CATMAINT run for Db2 12 runs. An application accessing CATALOG_LEVEL from a coexistent Db2 11 member of a data sharing group would see a value of V12R1M500 after the initial CATMAINT run for Db2 12 runs on a Db2 12 member.
The third and final new global session variable for continuous delivery is the DEFAULT_SQLLEVEL, which stores the default value of the SQLLEVEL SQL processing option (DECPSQLL). As with the others, the data type is VARCHAR(30) and it is maintained by the system with a schema of SYSIBM.
- vv is the version
- r is the release
- mmm is the modification level (such as 100, 500, 501)
For example, V12R1M501 identifies Db2 Version 12 Release 1 Function Level 501.
Keep these global variables in mind and use them as appropriate in your programs to ensure that the functionality you need is actually available to your program when it runs.
