• Antelope Release 5.10 Linux CentOS release 7.6.1810 (Core) 3.10.0 2020-05-12

 

NAME

dbviews - views versus tables in Datascope

DESCRIPTION

A relational database consists of base tables (relations) which each have records with a fixed set of fields. The RDBMS provides methods of manipulating the tables (joins, sorts, subsets, etcetera) and accessing those fields. One of the most important concepts is the view.

The result of manipulations of tables is always a view. In Datascope, the view is not a copy of the contents of base tables, but rather a collection of references to records in base tables. The result of subsets, sorts, and joins are simple views: every record in the view consists of a fixed set of database pointers identifying a particular record in a base table. Changing a field in a view actually changes the corresponding field in some base table.

More complex views -- grouped views, for example -- are not simply a collection of references to explicit records in base tables. Instead, there are some fields -- the fields on which the grouped view was formed -- which are copies of fields in base tables, and range references, usually to a range of records in a view (since a table must usually be sorted before applying the group operation).

ATTRIBUTES

MT-Safe ?

AUTHOR

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