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Announcing Function Level 509 in Db2 12 for z/OS

By Paul McWilliams posted Mon February 22, 2021 04:47 PM


You can now activate function level 509 in your Db2 12 for z/OS environment after you apply the PTF for APAR PH33015. Function level 509 introduces the following new capabilities in Db2 12.

Support for tamper-proof audit policies  

Tamper proof audit policies cannot be modified or stopped unless the user is authorized to access the audit policy profile in a security product that is external to Db2, such as RACF. This new audit capability prevents users with advanced Db2 privileges from unnecessarily modifying or stopping the audit policy, minimizing the possibility of loss of audit information. For more about this new capability, see the follow-on blog entry: Tamper-proof audit policies in Db2 12 function level 509. 

High availability for accelerator-only tables 

With high availability for accelerator-only tables you can now define an accelerator-only table in more than one accelerator. This capability enhances accelerator-only tables with high availability and workload balancing, including the following features: 

  • Rerouting a query to an available accelerator if the target accelerator is not available. 
  • Using the accelerator workload balancing algorithm to distribute queries based on the queue length on each accelerator. 

To create an accelerator-only table that is defined in multiple accelerators, specify a location alias that represents multiple accelerators in the IN ACCELERATOR clause of the CREATE TABLE statement. The accelerator-only table is defined in all accelerators that are associated with the location alias. 

Specify compression algorithms for specific tables, table spaces, or partitions  

Function level 509 introduces the capability to explicitly specify either the fixed-length or Huffman compression algorithm at the table, table space, or partition level by using new syntax in the CREATE TABLE, CREATE TABLESPACE, and ALTER TABLESPACE statements. The Db2 catalog is updated to indicate the compression algorithm used for each object.

A temporal RI enhancement to allow UPDATE or DELETE on a parent table 

An enhancement to the UPDATE and DELETE statements removes restrictions related to the temporal referential integrity (RI) support that was introduced in the original Db2 12 release. 

At application compatibility level V12R1M509 or higher, when an UPDATE statement with a FOR PORTION OF clause attempts to update the parent table in a temporal RI relationship, the update is allowed if the rules of temporal RI are not violated.  

Likewise, when a DELETE statement with a FOR PORTION OF clause attempts to delete from the parent table in a temporal RI relationship, the deletion is allowed, if the rules of temporal RI are not violated. 

At any lower application compatibility level, such UPDATE or DELETE statements for a parent table in an RI relationship are restricted with SQLCODE -4736. 

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