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a relational database management system must manage the database entirely through its relational capabilities.
null values are systematically supported independent of data type.
all information is represented logically by values in tables.
None of these.
the system should be able to perform all theoretically possible updates on views.
the logical description of the database is represented and may be interrogated by authorised users, in the same way as for normal data.
the ability to treat whole tables as single objects applies to insertion, modification and deletion, as well as retrieval of data.
null values are systematically supported independent ...