Collision detection and data corruption protection during an on-line database reorganization

A system comprising a processor configured to perform a method, the method comprising:

• identifying a set of records in a database for relocation during an on-line database reorganization (ODBR) process, each record associated with a unique record reorganization lock (RRL);
• relocating, by a computer, the set of records from a current location to a new location, the relocating including for each record in the set of records:
• requesting a record reorganization lock (RRL) associated with the record;
• receiving the RRL associated with the record, the RRL associated with the record configured to prevent access to both the current location and the new location of the record;
• retrieving data from the current location of the record;
• storing the data in the new location of the record;
• and
• releasing the RRL associated with the record;
• receiving a request to update a target record in the set of records with updated data, the receiving a request to update a target record overlapping in time with at least a portion of the relocating and the receiving a request to update a target record received from an application;
• requesting a RRL associated with the target record, the RRL associated with the target record configured to prevent access to both the current location and the new location of the target record, the requesting independent of the application;
• receiving the RRL associated with the target record;
• updating the target record, the updating comprising writing target data to the target record in the current location and writing the target data to the target record in the new location;
• and
• releasing the RRL associated with the target record.

A computer program product comprising a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:

• identifying a set of records in a database for relocation during an on-line database reorganization (ODBR) process, each record associated with a unique record reorganization lock (RRL);
• relocating, by a computer, the set of records from a current location to a new location, the relocating including for each record in the set of records:
• requesting a record reorganization lock (RRL) associated with the record;
• receiving the RRL associated with the record, the RRL associated with the record configured to prevent access to both the current location and the new location of the record;
• retrieving data from the current location of the record;
• storing the data in the new location of the record;
• and
• releasing the RRL associated with the record;
• receiving a request to update a target record in the set of records with updated data, the receiving a request to update a target record overlapping in time with at least a portion of the relocating and the receiving a request to update a target record received from an application;
• requesting a RRL associated with the target record, the RRL associated with the target record configured to prevent access to both the current location and the new location of the target record, the requesting independent of the application;
• receiving the RRL associated with the target record;
• updating the target record, the updating comprising writing target data to the target record in the current location and writing the target data to the target record in the new location;
• and
• releasing the RRL associated with the target record.