With the availability of PTF for APAR PH70028, you can now activate function level V13R1M509 to enable the following new capabilities in your Db2 13 for z/OS environment.
Converting Db2 catalog and directory objects to UTS
Function level 509 enables a process for converting table spaces for Db2 catalog and directory tables from deprecated non-UTS types to partition-by-growth universal table spaces (PBG UTS). This conversion improves performance, simplifies administration, and aligns catalog objects with modern Db2 storage architecture.
When you’re ready to convert your catalog objects, you can use the REORG TABLESPACE utility with the new CONVERTUTS option. The conversion process is designed to minimize disruption and can be performed incrementally, allowing you to convert objects at your own pace based on your operational requirements. You can customize and run the new DSNTIJCR sample job to complete the conversion for all remaining non-UTS table spaces in the Db2 catalog and directory.
Note that the preparation for this conversion began in function level 508, when CATMAINT created new table spaces with the DEFINE NO attribute. Function level 509 now enables the actual conversion process. Learn more
Subnet wildcard filtering for resource limit facility (RLF)
The Resource Limit Facility (RLF) now supports IPv4 and IPv6 subnet wildcards and local subsystem governing. These enhancements dramatically reduce the number of rows required in the DSNRLMTxx table by allowing a single entry to govern entire network blocks instead of maintaining individual IP address entries.
Function level 509 also adds support for the special IP address 127.0.0.1, which allows RLF rules to apply only to SQL originating from the local Db2 subsystem. Exact IP address entries continue to take precedence over subnet entries, providing flexibility in how you define and apply RLF rules. This enhancement significantly simplifies the management of large client environments. Learn more
Online ownership transfer of application objects
Security administrators can now satisfy business security mandates without causing application outages, thanks to new syntax in the TRANSFER OWNERSHIP statement for application objects. Starting at APPLCOMPAT level V13R1M509, you can transfer ownership of stored procedures, functions, and sequences online.
Before this enhancement, changing the ownership of these objects often required disruptions including invalidation of packages that use the object, and sometimes cascaded drops of dependent objects, frequently leading to application outages. The new capability enables seamless ownership transfers while maintaining application availability. Learn more
Utility history for SHRLEVEL information
Function level 509 enhances the utility history information in the Db2 catalog to record the SHRLEVEL option that was in effect for each utility execution. Database administrators and IBM Support can use this information to determine when concurrency problems might be caused by the SHRLEVEL option used for utility executions.
This enhancement provides valuable diagnostic information that helps troubleshoot performance and concurrency issues related to utility operations. Learn more
New catalog columns for STMT_HASHID2
More-granular hash values are now available to identify specific SQL statements, through new columns named STMT_HASHID2 and STMT_HASH2VER in several Db2 catalog tables.
For static SQL statements, these columns are added in the SYSIBM.SYSPACKSTMT and SYSIBM.SYSPACKSTMTCOPY catalog tables. The hash key values are based on the normalized statement text combined with other information such as the package name, collection ID, and selected bind options.
The existing QUERY_HASH column values are similar, but their hash keys are generated based on the SQL statement text only, so they don’t uniquely identify situations where statements with identical text are issued from different packages, with different bind options, or with different PREPARE attributes. The new STMT_HASHID2 columns provide this additional granularity. Learn more
I/O counts in real-time statistics
Function level 509 introduces object-level synchronous read I/O data into real-time statistics (RTS) to support improved analysis of read I/O behavior over time. This enhancement adds NSYNCREADIO columns to the SYSIBM.SYSTABLESPACESTATS and SYSIBM.SYSINDEXSPACESTATS RTS tables to record the count of synchronous read I/O operations at the object level.
The NSYNCREADIO columns complement the existing GETPAGES metric by providing object-level insight into synchronous read I/O, similar to the insight provided by QBSTRIO at the SQL query block level. This capability enables DBA tools and Db2 AI for z/OS to analyze and detect anomalies in object behavior more effectively. Learn more
Reduced false page P-lock contention in data sharing
Function level 509 reduces false page P-lock contention in data sharing environments by introducing a new lock hash algorithm for page sets of objects other than PBR RPN table spaces. The enhancement applies to page sets where the DSSIZE is greater than 64 GB and the page size is 4 KB, or the DSSIZE is greater than 128 GB and the page size is 8 KB.
These page sets include user objects as well as catalog and directory objects that might experience increased false page P-lock contention when they are converted to PBG UTS through the CATMAINT process.
To benefit from this enhancement, existing page sets must be reformatted after function level 509 is activated. You can use one of the following utilities: REORG TABLESPACE, REORG INDEX, REBUILD INDEX, or LOAD REPLACE. Page sets that are created after function level 509 is activated automatically use the new algorithm, so they are not affected by the false page P-lock contention. Learn more
Verification of earlier new-function APARs
As with all function levels since FL 504 in Db2 13, activation of function level 509 verifies that the PTFs are consistently applied in your Db2 environment for a series of earlier new-function APARs. The enhancements in these APARs can generally be used at any Db2 13 function level in each Db2 subsystem or data sharing member where the PTFs are applied. However, activating function level 509 guarantees that they are applied consistently in your Db2 environment and cannot be removed. To find these APARs, see the “Verifying function level” column in New-function APARs for Db2 13