Abstract: A method executed by a computer system for providing a visual interface Nor specifying relationships and correspondences between two graphically displayed database schemas in object oriented form. After displaying two schemas, selecting an object one from each and displaying their attributes. After selecting a pair of attributes if they are key attributes, comparing their domains and recording same and checking to determine if there is a mis-match as to data types. If either attribute is not a key attribute, checking to see if there is a mis- match of data types. If in either case there is no mismatch, then select a name for the combined attribute and deleting the attributes so combined from the list of attributes for each object. Repeating until all attributes of all objects of the two schemas have been combined, then generating a file containing all correspondences and a list of all assertions of correspondences.

Abstract: A method practiced by a computer system for generating SQL commands to create an integrated global schema. The input is two relational schemas in object-oriented form and a list of correspondences between components, object classes, objects and attributes. Based on correspondences object classes within one schema are folded into one object class, or relation, and likewise, based on correspondences one relation from each input schema is merged into a single relation of the integrated schema. This process is continued until no more object classes can be folded together and no more can be merged. SQL commands are generated based on specified correspondences between attributes depending upon whether a relation of the integrated relational schema was derived from only one relation of one of the input schemas, or is the result of the merger of two relations each from a different input schema. In the latter case, correspondences are based on the attributes of merged relations.

Abstract: A method for integrating the schemas of a plurality of independent and heterogeneous database management systems of a distributed database management system (DDBMS). The DDBMS includes a computer system in which the DDBMS resides and one or more subservient computer systems. The schemas of two of the independent database systems are fetched from the subservient computer systems. The schemas are converted from a relational database form to an object-oriented form. The schemas are then normalized and displayed graphically. Equivalencies are identified and the two schemas are integrated. These steps are repeated until the schemas of all data bases to be integrated have been integrated into a single integrated, or global schema.

Abstract: A method executed by a computer system for converting a database schema in relational form to a schema in object-oriented (00) form. The input is the schema of a database in relational form including all relations of the schema and the primary keys, reference keys, and attributes of each relation. A special data structure (SDS) is created for each primary key based on the number of attributes of the key. Each SDS becomes the basis of an object of the 00 schema produced. Attribute functions and cross-reference functions are created based on the SDSs and reference keys. SQL commands to map the relational input schema to the 00 output schema are identified.

Abstract: A method for graphically displaying an object-oriented schema on the screen of a computer system. The input is an object-oriented schema of a database in textual form. The input is parsed to identify the components of the schema. A connectivity matrix is developed in order to determine the number of interrelationships of objects. The screen is partitioned into cells, with each cell designed to hold an object and its attributes, with the object that has the maximum number of relationships with other objects being placed in the center cell of the grid, and related objects in adjacent (surrounding) cells. Relationships between objects and their attributes are identified by lines, arcs, labels, and arrows drawn on the screens of the display device of the computer system. The user can interface with the system by clicking on the graphical objects appearing on the computer screen.