METHOD FOR EDITING VIEWS CREATED BY JOINS

A method and apparatus for selectively allowing data presented in a join view to be modified is disclosed. Data presented in a join view is allowed to be modified if provided to the join view by a key-preserved table. A table is a key-preserved table with respect to a join view if each of the keys of the table is a key of the join view. Key-preserved tables may be identified by inspecting the definition of a join view to identify the base tables of the join view and to generate a graph. In the graph, each node corresponds to one of the base tables. Directed edges between nodes of the graph correspond to relationships, specified in the definition of the join view, between the base tables. The graph is reduced to strong components, each of which corresponds to a set of the base tables in which each base table in the set is routed to each other base table in the set by one or more directed edges. If a strong component in the resulting graph constitutes a unique source vertex, then each of the tables corresponding to the unique source vertex are key-preserved tables.