The following overview describes the general database parameters. For more information about other database parameters, see Special Database Parameters, Support Database Parameters and liveCache Database Parameters.
Changes to database parameters do not take effect until the database instance is restarted.
With the Database Manager CLI, you can change some database parameters even while the system is running.
General Database Parameters
Parameter |
Meaning |
How can I change this Parameter? |
CACHE_SIZE |
Size of the I/O buffer cache (in pages) |
Restart required after change |
INSTANCE_TYPE |
Database instance type You define the database instance type when you create the database instance and cannot change it later. |
Parameter cannot be changed |
KERNELVERSION |
Version of the database software When you install a new version of the database software, the database system updates the value of this parameter. |
Parameter cannot be changed |
LOG_MIRRORED |
Specifies whether the database system mirrors the log area (Log Mode) This parameter is relevant only when you create a mirror volume with the Database Manager CLI. The Database Manager GUI automatically sets this parameter when a mirror volume is created. |
Restart required after change |
LOG_SEGMENT_SIZE |
Size of a log segment (in pages). If automatic log backup is active, the database system automatically performs a log backup as soon as a log segment is full. |
Restart required after change |
MAXBACKUPDEVS |
Maximum number of files or tape devices in a group of parallel backup media |
Restart required after change |
MAXCPU |
Maximum number of processors to which the database system can distribute user tasks. Note that your computer’s operating system resources have to be available for other processes as well as the database system. |
Restart required after change |
MAXDATAVOLUMES |
Maximum number of data volumes |
Restart required after change |
MAXLOCKS |
Maximum number of entries in the lock list |
Restart required after change |
MAXLOGVOLUMES |
Maximum number of log volumes |
Restart required after change |
MAXUSERTASKS |
Maximum number of user tasks that are active at the same time and therefore the maximum number of database sessions. If this number has been reached, then no other user can log on to this database instance. If you choose a very high value for MAXUSERTASKS, the database system requires a lot of address space, particularly for local communication via shared memory. |
Restart required after change |
MCOD |
MCOD = Multiple Components One Database In SAP systems, indicates if other applications use the database |
Restart required after change |
RUNDIRECTORY |
Run directory of the database instance |
Restart required after change |