This Db2 for z/OS News from the Lab blog entry was originally published on 2019-06-26.

By Paul McWilliams.

We're proud to announce that Db2 12 for z/OS function level 505 becomes available for activation when you apply APAR PH09191. Function level 505 introduces the following new capabilities in Db2 12 for z/OS.

Improved Hybrid Transactional Analytical Processing performance

Performance improvements address the perceived latency between Db2 for z/OS and IBM Analytics Accelerator for z/OS in Hybrid Transactional Analytical Processing (HTAP) environments. The functional code was delivered in APAR PI98630.

Rebind phase-in for packages being used for execution

With rebind phase-in, Db2 can rebind packages concurrently with execution of the package. To support the concurrency, a rebind operation creates a new copy of the package. When the rebind operation finishes, new threads can use the new package copy immediately, and existing threads can continue to use the copy that was in use prior to the rebind (the phased-out copy) without disruption. This enhancement also enables gradual switching to previous access paths and runtime structures, by phasing-in the switch to the previous access path, allowing regression recovery without incurring an application outage. For the full story, see Rebind packages with fewer application outages in Db2 12 function level 505 The functional code was delivered in APAR PH12186.

New built-in functions for encryption and decryption using key labels

New built-in encrypt and decrypt data key functions simplify data protection. The new ENCRYPT_DATAKEY function converts a block of plain text to a block of encrypted text using a specified algorithm and key label, and several new DECRYPT_DATAKEY functions return the block of encrypted text from ENCRYPT_DATAKEY as a block of the datatype specified by the function used. The functional code was delivered in APAR PH09506. For a detailed look at how you can take advantage these new built-in functions, see Encrypting a column in Db2 without modifying the application.

Improved support of the DECFLOAT data type

You can now specify DECFLOAT columns in an index and as a key in a primary or unique key. Look for more details in a future post.The functional code was delivered in APAR PH09797.

Improved RUNSTATS performance with automatic page sampling by default

The default value of the STATPGSAMP subsystem parameter, which was recently introduced in Db2 12 by APAR PH07220, is changed so that SYSTEM has the same meaning as YES. With the new default behavior, the RUNSTATS utility always executes as if the TABLESAMPLE SYSTEM AUTO utility option is specified. That is, RUNSTATS always uses page sampling for universal table spaces, and it determines the sampling rate automatically. The only exception is if the RUNSTATS statement specifies TABLESAMPLE SYSTEM and a value other than AUTO. RUNSTATS uses the specified value in that case. The functional code was delivered in APAR PH07220.

Temporal and archive transparency support for WHEN clause on triggers

System-period temporal tables and archive-enabled tables can be referenced in WHEN clauses of both basic and advanced triggers, regardless of the settings of the SYSTIMESENSITIVE and ARCHIVESENSITIVE bind options. Time machine and transparent archive data retrieval are fully supported in the WHEN clause. The functional code was delivered in APAR PH09794.

Paul McWilliams is an information developer for Db2 for z/OS.