General Extended Support By Name By Class

SAP MaxDB Database Parameters (General)


AutoLogBackupSize

change: OFFLINE

 Size of the segments in which the log is saved and threshold value
 which causes the logs to be saved with automatic log backup.

 The lower and upper limits:
     LogIOClusterSize * 3 <= AutoLogBackupSize < LogVolumeSize*

 If no log segment size has been defined, 1/3 log is considered a log segment.

 (4 bytes integer)

CacheMemorySize

change: OFFLINE


 The value specifies the i/o capable memory used by different 
 MaxDB components in particular the data cache, converter and
 the shared catalog cache.

 Use the database monitoring to obtain information about the data cache
 hit rate and the performance of the system.

 The lower and upper limits are:
     800 <= CacheMemorySize < total RAM size

 (4 bytes integer)

MaxBackupMedia

default: 2

change: OFFLINE

 Maximum number of backup devices (e.g. tape drives) used in parallel
 for backup/recovery

 The lower and upper limits are:
     1 <= MaxBackupMedia <= 32

 (2 bytes integer)

MaxCPUs

default: 1

change: OFFLINE

 The value of MaxCPUs has a great influence on the distribution of
 the database kernel tasks to operating system threads (UKTs). 
 
 The parameter defines the maximum of CPU-Cores that are occupied by 
 the operating system threads (UKTs) that are generating the main load.

 If the computer is used as database server exclusively, MaxCPUs should
 correspond to the actual number of CPU-Cores of the machine.
 Otherwise reduce the value by the number of CPU-Cores occupied by other applications.

 The lower and upper limits are:
     1 <= MaxCPUs <= MaxUserTasks

 ( MaxCPUs <= actual number of CPU-Cores )

 (2 bytes integer)

MaxDataVolumes

default: 1

change: OFFLINE

 Maximum number of data volumes

 Allow for a reserve number of volumes which enables you to add
 volumes during database operation.

 The lower and upper limits are:
     11 <= MaxDataVolumes < POWER( 2, ConverterVolumeIdLayout )

 (2 bytes integer)

MaxLogVolumes

default: 1

change: OFFLINE

 Maximum number of log volumes,
 mirrored log volumes are not included.

 Allow for a reserve number of volumes which enables you to add
 volumes during database operation.

 The lower and upper limits are:
     1 <= MaxLogVolumes <= 32

 (2 bytes integer)

MaxSQLLocks

default: 2500

change: OFFLINE

 Maximum number of lock list entries in which the current and requested
 row and table locks for all users are held.

 Specification depends on the used application, the number of
 users, and the isolation level.

 Use the database monitoring to obtain information about the number
 of Max. Entries, Escalations, and Average Used Entries.

 The lower limits are:
 MaxSQLLocks >= 500
 AND/OR
 MaxSQLLocks >= (((TransactionLockManagementStripes + TableLockManagementStripes + RowLockManagementStripes) * 100) DIV 3

 There should be at least 10 row locks per transaction

 (4 bytes integer)

MaxUserTasks

default: 50

change: OFFLINE

 Maximum number of simultaneously active users (database sessions).
 Overconfiguration exceeding the actual requirement results in an
 excessive demand for address space (especially shared memory).

 (2 bytes integer)

MCODIndicator

default: "NO"

possible values: "YES" "NO"

change: OFFLINE

This parameter (Multiple Components One Database) shows applications
whether they have exclusive access to the database or not.

Valid types are:
  "YES"     for there are other applications using the database
  "NO"      for there are no other applications


OmsMaxHeapSize

default: 0

change: OFFLINE

  Number of KB useable for OMS heap

  0 means : OMS heap is not limited by the liveCache

  otherwise the lower limit is

  OmsMaxHeapSize >= 100000

  (4 bytes integer)

RunDirectoryPath

change: OFFLINE

 Path where context and diagnosis information is stored
 for this database instance.

 (char(256))

UseMirroredLog

default: "NO"

possible values: "YES" "NO"

change: OFFLINE


 Specifies whether the database system mirrors the log area. This kind of
 mirroring should be only used if hardware-based mirroring is not possible.

 'YES': log area is mirrored

 'NO' : log area is not mirrored
 
 (char(8))