Method and system of externalising/internalising data record that allow processing of part or all of the record

A method of external data storage in a system including a primary processing device, having a processor and a primary data storage unit, adapted to run application programs for processing active records in the processor and configured to store data belonging to active records in the primary data storage unit;

• and a secondary data storage system, accessible to the primary processing device, which method includes:
• loading data belonging to an active record into the primary data storage unit;
• externalising the record by transferring at least a piece of data belonging to the record to the secondary data storage system for storage, wherein the externalising of the record includes making a call by an application program using data belonging to the record to an interface, arranged to transfer the piece of data to the secondary data storage system;
• dividing the piece of data into a plurality of parts, receiving a plurality of externalisation messages, each identifying a data section including data corresponding to an associated one of the plurality of parts and transferring at least the identified data section in response to each externalisation message;
• and
• calculating an authentication value for each part of the piece of data and including data reflecting the authentication value in the data section that includes data associated with that part, wherein the authentication value for at least one part is calculated using information derived from a further part as input.

A method of external data storage in a system including a primary processing device, having a processor and a primary data storage unit, adapted to process active records in the processor and configured to store data belonging to active records in the primary data storage unit;

• and a secondary data storage system, accessible to the primary processing device, which method includes
• loading data belonging to an active record into the primary data storage unit and
• externalising the record by transferring at least a piece of data belonging to the record to the secondary data storage system for storage, wherein the method includes
• storing information reflecting a version count for the externalised record and incrementing the version count prior to externalising the record;
• dividing the piece of data into a plurality of parts, receiving a plurality of externalisation messages, each identifying a data section including data corresponding to an associated one of the plurality of parts and transferring at least the identified data section in response to each externalisation message;
• and
• calculating an authentication value for each of the plurality of parts of the piece of data and including data reflecting the authentication value in the data section that includes data associated with that part, wherein the authentication value for at least one part is calculated using information derived from a further part as input.