There are a number of changes to registry and environment variables to take advantage of new and changed functionality in Version 10.1.
These environment and registry variables are new in Version 10.1:
Registry variable | Description |
---|---|
DB2_ALLOW_WLB_WITH_SEQUENCES | You can use this registry variable to control whether applications that access sequences are allowed to participate in workload balancing. |
DB2_BCKP_INCLUDE_LOGS_WARNING | Starting in Version 10.1 Fix Pack 2, you can use this new variable to specify that online backups can succeed even if they fail to include all of the necessary log files. |
DB2_BCKP_PAGE_VERIFICATION | Starting in Version 10.1 Fix Pack 2, you can use this new variable to specify that DMS and AS page validation occurs during a backup. |
DB2_BACKUP_USE_DIO | You can use this registry variable to have a backup image file directly written to disk, bypassing the file cache, potentially leading to better memory utilization on Linux platforms. This registry variable is available in V10.1 Fix Pack 1 and later fix packs. |
DB2_HISTORY_FILTER | You can use this variable to specify operations that are not to modify the history file, thereby reducing potential contention on the history file This registry variable is available in V10.1 Fix Pack 1 and later fix packs. |
DB2_INDEX_PCTFREE_DEFAULT | You can use this registry variable to specify what percentage of each index page to leave as free space when building the index. |
DB2_MAX_GLOBAL_SNAPSHOT_SIZE | Starting in Version 10.1 Fix Pack 2, you can use this new variable to specify the maximum size a snapshot or snapshot estimate can be, thereby preventing large global snapshots from causing memory usage spikes. |
DB2_MCR_RECOVERY_PARALLELISM_CAP | You can use this registry variable to limit how many active databases are recovered in parallel on a member during member crash recovery. You can use this variable only in a DB2® pureScale® environment. |
DB2_SAS_SETTINGS | This DB2 registry variable is the primary point of configuration for in-database analytics with the SAS embedded process. |
DB2_SMP_INDEX_CREATE | Introduced in Version 10 Fix Pack 4, this DB2 registry variable overrides the default number of agents used to scan and sort the index data when building or rebuilding an index. |
DB2TMPDIR | This variable is used to specify a path for the temporary files directory. |
DB2_XSLT_ALLOWED_PATH | You can use this registry variable to control whether the DB2 instance refers to external entities defined inside of an XSLT stylesheet. |
Registry variable | New values |
---|---|
DB2_PMODEL_SETTINGS | You can now use this variable's new SRVLST_EQUAL_WEIGHT option to override the default behavior in which member weights are computed based on load, and have non-zero member weights in the server list always be identical. |
Registry variable | Changed behavior |
---|---|
DB2_ANTIJOIN | Starting in Version 10.1 Fix Pack 1, the default for this variable in non-ESE environments is EXTEND, meaning that the optimizer searches for opportunities to transform both NOT IN and NOT EXISTS subqueries into anti-joins. |
DB2BPVARS | The NUMPREFETCHQUEUES and the PREFETCHQUEUESIZE option of this variable have been discontinued as optimization improvements render these options obsolete. The DB2BPVARS registry variable is still deprecated. |
DB2_EXTENDED_OPTIMIZATION | The ENHANCED_MULTIPLE_DISTINCT setting has been deprecated and might be removed in a future release. Version 10.1 includes enhancements to improve the performance of multiple distinct queries. These enhancements are supported in all environments including partitioned database and DB2 pureScale environments. These enhancements are enabled by default in newly created databases and upgraded databases where this registry variable is not set to ENHANCED_MULTIPLE_DISTINCT. If you keep this setting, the previous release behavior is maintained. You should remove this setting to make the new enhancements available and benefit from better query performance. |
DB2_NO_FORK_CHECK | This registry variable is no longer deprecated. Continue to use this variable to have the DB2 runtime client minimize checks to determine if the current process is a result of a fork call. |
DB2NTNOCACHE | This registry variable is no longer deprecated. Continue to use this variable to override the undocumented 192 MB limit for the cache. |
Take advantage of enhanced functionality or new features by adopting new functionality through the use of new registry variables or new values for existing registry variables.
For new registry variables or changes to existing registry variables that result in DB2 server behavior changes, adjust your existing applications or scrips.
Review the list of deprecated and discontinued registry variables to learn about additional changes that might impact your applications and scripts and determine whether you have to adjust them or not.