DB2 Version 9.7 for Linux, UNIX, and Windows
DB2 Version 9.7 for Linux, UNIX, and Windows
Version 9.7 contains a number of new and changed database configuration parameters.
Due to new features and functionality, Version 9.7 contains a number of new database configuration parameters.
| Parameter name | Description | Details |
|---|---|---|
| auto_reval | Automatic revalidation and invalidation | This configuration parameter controls the revalidation and invalidation semantics. This parameter is dynamic, meaning that a change in its value takes effect immediately. You do not have to reconnect to the database for the change to take effect. |
| blocknonlogged | Block non-logged activity | This configuration parameter prevents the creation of tables that allow non-logged activity. |
| cur_commit | Currently committed | This configuration parameter controls the behavior of cursor stability (CS) scans. |
| date_compat | Date compatibility | This parameter indicates whether the DATE compatibility semantics associated with the TIMESTAMP(0) data type are applied to the connected database. |
| dec_to_char_fmt | Decimal to character function configuration parameter | This configuration parameter controls the result of the CHAR scalar function and the CAST specification for converting decimal to character values. |
| mon_act_metrics | Monitoring activity metrics | These parameters control the collection of metrics and event monitor data at the database level including the new lock event monitor, and lock-related messages notification level. During database upgrade, these parameters are set to NONE, except for mon_deadlock which is set to WITHOUT_HIST, mon_lw_thresh which is set to 5 000 000, mon_lck_msg_lvl which is set to 1, and mon_pkglist_sz which is set to 32, so that there is no change in behavior from previous releases. |
| mon_deadlock | Monitoring deadlock | |
| mon_locktimeout | Monitoring lock timeout | |
| mon_lockwait | Monitoring lock wait | |
| mon_lw_thresh | Monitoring lock wait threshold | |
| mon_lck_msg_lvl | Monitoring lock event notification messages | |
| mon_obj_metrics | Monitoring object metrics | |
| mon_pkglist_sz | Monitoring package list size | |
| mon_req_metrics | Monitoring request metric | |
| mon_uow_data | Monitoring unit of work events | |
| stmt_conc | Statement concentrator | This configuration parameter enables statement concentration for dynamic statements. The setting in the database configuration is used only when the client does not explicitly enable or disable statement concentrator. |
The following table lists the database configuration parameters with changes to their default values.
| Parameter name | Description | Version 9.5 default value | Version 9.7 default value |
|---|---|---|---|
| logbufsz | Log buffer size | 8 pages (each 4KB) | 256 pages ( each 4 KB) |
The following database configuration parameters have changed behaviors or have new ranges in Version 9.7.
| Parameter name | Description | Version 9.7 change |
|---|---|---|
| applheapsz | Application heap size | Due to optimization enhancements to match MQTs, the requirement for application heap has increased. If this parameter is set to AUTOMATIC, this setting accounts for the new requirements. If you cannot set this parameter to AUTOMATIC or increase its value, reduce the number of MQTs considered for a given query by using optimization profiles. For more information, see Anatomy of an optimization profile. |
| database_memory | Database shared memory size | The self tuning memory manager (STMM) has an improved ability to adjust the database shared memory usage on Solaris Operating Environment. If database_memory is set to AUTOMATIC on a Solaris operating system, the database manager uses pageable memory for the database shared memory. As a result, the DB2® database system uses smaller memory pages by default and you might notice some performance degradation. |
| dbheap | Database heap | The database manager can now determine when to apply row compression to temporary tables that meet certain criteria to improve query performance. Memory allocated for database heap is used to create the compression dictionary and released once the dictionary is created. If you are using row compression and temporary tables eligible for compression, ensure that you have enough space to create the dictionary by setting the dbheap parameter to AUTOMATIC. For details about temporary table compression, see Table compression. |
| locklist | Maximum storage for lock list | The limit for this parameter is now 134,217,728 pages (4 KB). |
| logbufsz | Log buffer size | A log sequence number (LSN) uses now 8 bytes. In previous releases, LSN was 6 bytes in length. You might need to increase the value of this parameter according to your database logging activity. For more information, see Maximum limit of log sequence numbers has increased. The maximum limit for logbufsz has been changed to 131 070. The maximum limit for logfilsiz has been changed to 1 048 572. |
| logfilsiz | Size of log files | |
| logprimary | Number of primary log files | |
| num_db_backups | Number of database backups | Starting in Fix Pack 5, DB2 counts merged backups as full, non-incremental backups when determining the number of backups to retain. |
| pckcachesz | Package cache size | To support XML Explain,
package cache memory requirements have increased from 10 to 25 percent.
The impact from the database upgrade should be minimal because of
the small size of this cache. By setting this parameter to AUTOMATIC,
the new requirements are taken into account. For upgraded databases, the INLINE LENGTH default value is the maximum size of the LOB descriptor. LOB data is inlined when the length of the LOB data plus the overhead do not exceed the INLINE LENGTH value. Therefore, if the LOB data length plus the overhead is less than the LOB descriptor size for the LOB column, the LOB data is implicitly inlined in a table row after the database upgrade. Storing LOB data as inlined might require that you increase the pckcachesz database configuration parameter. By setting this parameter to AUTOMATIC, the new requirements are taken into account. The maximum limit for pckcachesz on 64-bit operating systems has been changed to 2 147 483 646. |
| Parameter name | Description | Details and resolution |
|---|---|---|
| dyn_query_mgmt | Dynamic SQL and XQuery query management | This configuration parameter is deprecated because it is Query Patroller specific. With the new workload management features introduced in DB2 Version 9.5, Query Patroller and its components have been deprecated in Version 9.7 and might be removed in a future release. |