Data storage structure in JT logic based databases

For the unique identification more attributes (columns) are applied in rational databases.
In practice, attributes within a type are defined in same data table.
Introducing new entity attributes requires the modification of the existing data tables and applications that use these data tables.
In JT logic based databases, records with the same ID values identify one entity called virtual record.
Virtual records with the same value of the “belonging to the virtual data table” attribute form a data table called virtual data table.