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    The use of the Data Dictionary is one of the essential features of FileMan.

    Instead of writing individual programs that control input and output from a File,

    FileMan stores the definitions of the File contents (called fields) in the Data Dictionary.

    The programs of FileMan then use the definitions in the Data Dictionary to construct

    programs that allow one to search, sort, load, delete, and print data in the File.

    In a language like SQL, the Data Dictionary would be called a schema. In truth,

    it has much more about it than the SQL schema has. The Data Dictionary has

    many advanced features, like cross-references, indices, triggers, bulletins, and

    identifiers to be truly a superset of an SQL schema.  In some ways, the Data 

    Dictionary defines the permanent data stored in a File with associated code

    in the same way that an object definition in another programming language

    is stored, complete with specialized code to filter bad values on input, and

    produce good values on output.

     

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      Thanks a lot Mr.David Whitten

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