UDS/SQL allows you to extend the user realms and DBDIR as well as DBTTs, and thus the number of possible records for the record type of a user schema, during live database operation. If necessary, DBTT and realm extension is performed automatically by the Independent DBH or the Linked-in DBH. This functionality, which is referred to below as "online realm extension" or "online DBTT extension", makes it possible to prevent interruptions to database operation. This results in a high level of availability of the data managed in UDS/SQL (see also chapter “High availability”).
Administering online extension includes the following steps:
Checking and setting system requirements for online extension (see section “System requirements for online extension”).
Activating and monitoring online realm extension and online DBTT extension (see section “Free place administration during realm extension” and section “Activating online DBTT extension”).
Irrespective of the activation of the online realm extension and online DBTT extension, the updating utility routines automatically extend the realms of the database being processed or the DBTTs of the record types in the DBDIR and DBCOM on demand (see section “Automatic realm extension by means of utility routines”).
Relocation and compression of stored data can also be performed during live operation (see section “Online reorganization with the UDS online utility”)