The database system logs all database transactions that change application data or the database catalog. It writes information about these changes into log entries. If necessary, the system can later use these log entries to roll back or repeat SQL statements.
Use one of the following database tools:
Database Studio, Database Manager CLI, or CCMS (in SAP systems only)
The log settings specify the most important logging properties.
Name |
Description |
---|---|
Log mode |
Specifies whether the database system supports software-based mirroring of the log volumes.
|
Overwrite mode for the log area |
Specifies whether the database system can overwrite redo log entries in the log area even if they have not been backed up.
If overwrite mode is on and you switch it off, you then have to carry out a complete data backup. |
Redo log management |
Specifies whether the database system writes redo log entries.
If redo log management is off and you switch it back on, you then must carry out a complete data backup. |
More information:
Database Studio, Changing Log Settings
Database Manager CLI, param_addvolume
To specify further logging properties, for example the log segment size or the number of log volumes, use database parameters.
More information: Database Parameters
Log entries are stored in the log area. If you need to increase the size of the log area, add log volumes.
Note that when the log area is full, you first need to carry out a log backup.
Caution
Adding a new log volume will not immediately reduce the filling level of the log area. The system will only use the new log volume after you have carried out a log backup.
More information:
Database Studio, Adding Log Volumes
Database Manager CLI, param_addvolume
Database Administration in CCMS, Log Area
Concepts of the Database System, How Databases Log Data Changes