To avoid interruptions to database operation, a number of the database configuration settings can be modified during live operation:
You can add or drop databases by means of the DAL commands ADD DB and DROP DB.
You can similarly add or drop individual realms, using the commands ADD RN and DROP RN. This makes it unnecessary in many cases to drop the entire database when performing necessary repair or structuring work, thus keeping the impact on live operation to a minimum.
You can modify the assignment of volumes for RLOG files which are to be newly created, using the DAL commands MODIFY LOG, MODIFY LOG-2 and MODIFY LOG-SIZE.
You can modify spare volumes for RLOG files, using the command MODIFY RESERVE.
You can modify the configuration parameters for distributed processing, using the DAL commands &ADD, &CHANGE, &DROP, &LOCK, &PWD, &SAVE, &SYN and &UNLOCK.
You can switch ALOG and RLOG files by means of the commands DAL CHECKPOINT and NEW RLOG.
If the free space in a realm has been depleted by a substantial number of insertions, or if it has fallen below a defined threshold value, the DBH can automatically extend the realm during live operation (see chapter “Resource extension and reorganization during live operation”).
You can modify an existing UDS-SQL pubset declaration, note the modification using the DAL NEW PUBSETS command, and then activate it using DAL PERFORM.
If the maximum number of records for a record type is reached when new records are stored then the DBH can automatically extend the DBTT during operation (see chapter “Resource extension and reorganization during live operation”).