CIM mapping method

Abstract

The invention discloses a CIM (common informatoin model) mapping method which comprises the steps as follows: building meta-model descriptions of a class and an object respectively to remove semantic differences related wtih the class and the object from the meta-model systems of the class and the object; and mapping meta-models to a relational database so as to build the database tables of the two meta-models, namely a pattern relation table collection (called as a pattern library) formed by mapping the class meta-model and an object relation table collection (called as an object library) formed by mapping the object meta-model. The database built by the method has limited number of tables; and as the meta-models are universal, the situation means that the table struture is stable and the arbitrary expansion requirement and the referential integrity constraint on an infomation model in a CIM appliation can be met.

Description

technical field [0001] The invention relates to a relational database mapping technology Background technique [0002] Most of the implementations of the existing Common Information Model ("CIM") come from the Object Management Group ("OMG") "Utility Management System (UMS) Data Access Facility Specification" Appendix C - SQL Examples . This document proposes a paradigm for mapping GDA interfaces into SQL statements. This leads to a question: how to map the CIM model described based on the object-oriented model to the relational database. [0003] In the object model, there are various relationships between objects, such as association, combination, aggregation, inheritance, etc., which cannot be directly expressed in the relational database, which is the so-called relationship between the object model and the relational model. "impedance mismatch". In order to solve these problems, the O / R (object-relational) mapping method based on the structure mapping mode is mostly ...

AI Technical Summary

Problems solved by technology

This leads to a question: how to map the CIM model based on the object-oriented model description to the relational database

There are at least hundreds of classes in the CIM object model, plus the complex relationship between classes, the object-relational model established based on this mapping method has a huge number of tables, which leads to poor maintainability of the system

[0010] 2. A large number of join operations - due to the existence of a large number of relational tables, importing an object requires multiple join operations, which usually loses the performance of database operations, although single-table inheritance and specific table inheritance can avoid problems caused by inheritance relationships. The connection operation, but the single table inheritance also brings waste of storage space. The specific table inheritance allows an object to be obtained from a table, but this causes the scalability of the system and the referential integrity of the data.

At the same time, the existence of object class relationship still makes a large number of connection operations unavoidable when object references

[0011] 3. Table record "expansion" - this situation is especially reflected in the use of class table inheritance, because each superclass needs to save a corresponding record of the subclass, which directly leads to an increase in the number of superclass table records

This mapping method appears to be somewhat difficult

Images