liveCache Database Parameters 
The following overview describes database parameters belonging to the liveCache Database Parameters group. They can only be used for SAP liveCache databases.
For information about other database parameters, see
To change the values of database parameters, use one of the following database tools: Database Studio, Database Manager CLI, or CCMS (in SAP systems only). More information:
Database Studio, Changing Database Parameters
Database Manager CLI Tutorial, Changing the Values of Database Parameters
Database Administration in CCMS, Parameters
Most changes to database parameters take effect only after the database has been restarted.
However, you can change individual database parameters while the database is running, that is in the ONLINE or ADMIN operational state (see the description of individual database parameters for more information). For these changes you can define when they are to become effective:
Until the next restart
After the next restart
Immediately and permanently
If you change a database parameter whose value is normally calculated by the system, then the system will consider this user-defined value for all subsequent recalculations of database parameter values. The system discards and recalculates this user-defined value only if it is not within the permitted value range (for example, after the database software has been updated).
Note
Starting with version 7.7.03 of the database software, the names of many database parameters have changed.
Some database parameters have also been designated obsolete. These parameters have either been removed already or will be removed in one of the next database versions.
More information: Obsolete Database Parameters
Name (from version 7.7.03) |
Old Name (up to and including version 7.7.02) |
Description |
Change Restrictions |
More Information |
|---|---|---|---|---|
MinRetentionTime MaxRetentionTime |
MIN_RETENTION_TIME MAX_RETENTION_TIME |
Specifies (in min) when the garbage collectors start deleting the history data (undo log entries and links to them) The garbage collectors start deleting the history data in the following cases:
|
Can be changed in ONLINE or ADMIN operational state |
Concepts of the Database System, How Databases Log Data Changes |
OmsHeapThreshold |
OMS_HEAP_THRESHOLD |
Specifies memory usage by the OMS heap (in %) |
Changes only apply after a restart of the database |
- |
OmsMaxHeapSize |
OMS_HEAP_LIMIT |
Specifies the maximum size of the OMS heap (in KB) |
Changes only apply after a restart of the database |
- |
OmsSubHeaps |
OMS_HEAP_COUNT |
Specifies whether the OMS heap is divided into segments If the OMS heap is not divided into segments, the internal heap memory management locks the entire OMS heap whenever a database procedure requests or releases memory. |
Changes only apply after a restart of the database |
Concepts of the Database System, Working Memory Areas |
OmsVersionThreshold |
OMS_VERS_THRESHOLD |
Specifies memory usage by the OMS heap (in KB) |
Changes only apply after a restart of the database |
- |