Automatic storage of persistent ASN.1 objects in a relational schema

• US 5,291,583 A
• Filed: 12/14/1990
• Issued: 03/01/1994
• Est. Priority Date: 12/14/1990
• Status: Expired due to Fees

• Current Assignee: Racal-Datacom, Inc. (Thales SA)
• Original Assignee: Racal-Datacom, Inc. (Thales SA)
• Inventors: Bapat, Subodh
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): VU, VIET DUY
• Application Number:
  US07/628,120
• Time in Patent Office: 1,173 Days
• Field of Search: 395/600, 395/500
• US Class Current: 717/137
• CPC Class Codes: G06F 16/284 Relational databases

Abstract

A translator for translating objects defined in Abstract Syntax Notation such as ASN.1 to a relational database schema permits persistent storage of object instances as records in a relational database. Object classes are mapped to entity tables with object instances represented by entity records. Simple attributes are mapped to primitive typed attribute columns and package or group attributes are mapped to separate dependent entity tables. Derived attributes are represented by joins of the parent and child entity records.

Claims

1. A method for a computer to translate an Abstract Syntax Notation object class hierarchy into a relational schema, comprising in combination the steps of:

providing said computer with a computer memory;

providing in said computer memory a first computer program having at least one Abstract Syntax Notation class hierarchy organization of object-oriented information and being in source code form, said class hierarchy organization comprising at least one parent class of objects having a first attribute and one derived class including at least one of said objects of said parent class, said derived class having a second attribute, said derived class inheriting said first attribute from said parent class;

analyzing said first computer program with a second computer program to locate automatically said class hierarchy organization;

using said second computer program to create automatically from said located class hierarchy organization a first source code routine in said computer memory for defining a first table structure, corresponding to said parent class, including a first table name, said first table structure including;

a first instance identifier field for storing a unique first instance identifier for each particular object instance of one of said objects, and

a first attribute field for storing an attribute instance of said first attribute for said each particular object instance,

said first instance identifier field and said first attribute field composing a record of said first table structure;

using said second computer program to create automatically from said located class hierarchy organization a second source code routine for defining a second table structure, corresponding to said derived class, including a second table name, said second table structure including;

a second instance identifier field for storing a second instance identifier which identifies said particular object instance of said one of said objects included in said derived class,

and a second attribute field for storing an attribute instance of said second attribute for said particular object instance of said one of said objects included in said derived class,

said second instance identifier field and said second attribute field composing a record of said second table structure; and

referencing said second identifier field to said first identifier field.

2. The method of claim 1, wherein said referencing step comprises placing identical said instance identifiers in said first and second instance identifier fields.

3. The method of claim 2, further comprising a step of using said second computer program to create automatically a third source code routine in said computer memory for joining said record of said first table structure to said record of said second table structure by using said instance identifier in said first and second instance identifier fields to extract said attribute instances of said first and second attribute fields for said particular object instance, whereby said derived class inheriting said first attribute from said parent class of said class hierarchy is preserved in said relational schema.

4. The method of claim 1, further comprising a step of using said second computer program to create automatically a third source code routine in said computer memory for querying said table structures using a "JOIN" operator from SQL to find said instances of said attributes in said records having said first and second instance identifier fields referenced.

5. The method of claim 3, further comprising a step of compiling said first computer program and said third source code routine to create a run-time computer program stored in said computer memory.

6. The method of claim 5, further comprising a step of storing said table structures in a persistent media operatively coupled to said computer.

7. The method of claim 1, further comprising a step of using said second program for generating a source code routine to create a set of dictionary tables which contain information adequate to define the Abstract Syntax Notation object class hierarchy relationship, object instance containment hierarchy and object instance name mapping.

8. The method of claim 1, wherein said steps of using said second computer program to create said source code routines includes creating said source code routines for constructing SQL commands to create said table structures;

and further including the steps of providing a relational database management system stored in a persistent memory and sending said SQL commands to said relational database management system to cause said table structures to be generated and stored in said persistent memory.

9. The method of claim 1, further comprising a step of using said second computer program to generate a source code routine for creating a view of said second table structure which includes a join into said first table structure.

10. The method of claim 1, further comprising a step of using said second program to automatically provide additional source code routines for storage, deletion and retrieval of object instances in said table structures.

11. The method of claim 1, further comprising a step of using said second computer program to generate a source code routine for creating indexes on said table structures.

12. The method of claim 1, further comprising a steps of:

ascertaining that one of said attributes is of an ASN.1 MULTI-VALUED type;

defining a third relational table having an third instance identifier field for storing an instance identifier and a third field for storing instances of said MULTI-VALUED attribute; and

referencing said third instance identifier field to said first instance identifier field.

13. The method of claim 1, further comprising a steps of:

ascertaining that one of said attributes is of an ASN.1 SET OF type of unspecified size;

defining a third relational table having an third instance identifier field for storing an instance identifier and a third field for storing instance of said SET OF attribute; and

referencing said third instance identifier field to said first instance identifier field.

14. The method of claim 1, further comprising a steps of:

ascertaining that one of said attributes is of an ASN.1 SEQUENCE OF type of unspecified size, said SEQUENCE OF type attribute having a collection of ordered components;

defining a third relational table having an third instance identifier field for storing an instance identifier, a third field for storing instances of said SEQUENCE OF attribute and a sequence index field for storing an order of appearance of said components of said SEQUENCE OF attribute; and

referencing said third instance identifier field to said first instance identifier field.

15. The method of claim 1, further comprising:

ascertaining that one of said attributes is of an ASN.1 SET type having a predetermined plurality of components;

defining a plurality of columns in said first relational table corresponding with said predetermined plurality of components.

16. The method of claim 1, further comprising:

ascertaining that one of said attributes is of an ASN.1 SET OF type of specified size having a predetermined plurality of components;

defining a plurality of columns in said first relational table corresponding with said predetermined plurality of components.

17. The method of claim 1, further comprising:

ascertaining that one of said attributes is of an ASN.1 SEQUENCE type having a predetermined plurality of components;

defining a plurality of columns in said first relational table corresponding with said predetermined plurality of components.

18. The method of claim 1, further comprising:

ascertaining that one of said attributes is of an ASN.1 SEQUENCE OF type of specified size having a predetermined plurality of components;

defining a plurality of columns in said first relational table corresponding with said predetermined plurality of components.

19. The method of claim 1, further comprising:

ascertaining that one of said attributes is of an ASN.1 CHOICE type having a predetermined plurality of choice components;

defining a plurality of columns in said first relational table corresponding with said predetermined plurality of choice components.

20. The method of claim 1, further comprising a steps of:

ascertaining that one of said parent and derived object classes possesses a CONDITIONAL PACKAGE;

defining a third relational table having an third instance identifier field for storing an instance identifier and a third field for storing instances of said CONDITIONAL PACKAGE; and

referencing said third instance identifier field to said first instance identifier field.

21. The method of claim 20, further comprising:

examining attributes of the CONDITIONAL PACKAGE to ascertain a type associated with each said attribute of said CONDITIONAL PACKAGE, where said type is one of primitive type, SET, SET OF with specified size, SET OF with unspecified size, SEQUENCE, SEQUENCE OF with specified size, SEQUENCE OF with unspecified size, CHOICE, MULTI-VALUED, ATTRIBUTE GROUP and CONDITIONAL PACKAGE;

processing each of said attributes in accordance with said type.

22. The method of claim 1, further comprising:

ascertaining that one of said parent and derived object classes possesses an ATTRIBUTE GROUP;

defining a third relational table having an third instance identifier field for storing an instance identifier and a third field for storing instances of said ATTRIBUTE GROUP; and

referencing said third instance identifier field to said first instance identifier field.

23. The method of claim 22, further comprising:

examining attributes of the ATTRIBUTE GROUP to ascertain a type associated with each said attribute of said ATTRIBUTE GROUP where said type is one of primitive type, SET, SET OF with specified size, SET OF with unspecified size, SEQUENCE, SEQUENCE OF with specified size, SEQUENCE OF with unspecified size, CHOICE, MULTI-VALUED, ATTRIBUTE GROUP and CONDITIONAL PACKAGE;

processing each of said attributes in accordance with said type.

24. The method of claim 1, further comprising:

ascertaining that one of said attributes is of an ASN.1 primitive type;

defining a column in said first relational table corresponding with said primitive type.

25. An apparatus for translating information represented as an Abstract Syntax Notation object-class hierarchy into a relational table schema, comprising in combination:

central processing means;

computer memory means, operatively coupled to said central processing means, for temporary storage of information;

a computer program, stored in said computer memory means in source code form, including at least one Abstract Syntax Notation data organization in the form of said object class hierarchy, said object class hierarchy being for object-oriented data and including at least one parent class of objects having a first attribute and one derived class of at least one of said objects having a second attribute, said derived class inheriting said first attribute from said parent class;

schema compiler means, stored in said computer memory, for locating automatically said object class hierarchy in said computer program and for translating said object class hierarchy into said relational table schema;

said schema compiler means including first table means for defining automatically in said relational table schema a first table structure, corresponding to said parent class, including a first table name, said first table structure including;

a first instance identifier field for storing a first instance identifier which identifies a particular object instance of said one object, and

a first attribute field for storing an attribute instance of said first attribute for said one object,

said first instance identifier field and said first attribute field comprising a record of said first table structure;

said schema compiler means further including second table means for defining automatically in said relational table schema s second table structure, corresponding to said derived class, including a second table name, said second table structure including;

a second instance identifier field for storing a second instance identifier which identifies said particular object instance of said one object,

and a second attribute field for storing an attribute instance of said second attribute for said one object,

said second instance identifier field and said second attribute field comprising a record of said second table structure; and

said schema compiler means further including reference means for said relational table schema to reference said second instance identifier field to said first instance identifier field.

26. The Apparatus of claim 25, wherein said schema compiler means further includes joining means for creating automatically said relational table schema to have means for extracting from said table structures said instances of said first and second attributes for said particular object instance by using said referencing of said second identifier field to said first identifier field, whereby said derived class inheriting said first attribute from said parent class of said class hierarchy is preserved in said relational schema.

27. The apparatus of claim 25, wherein said reference means is adapted for placing identical instance identifier information in said first and second instance identifier fields.

28. The apparatus of claim 27, further comprising means for joining said record of said first table structure to said record of said second table structure by using said instance identifier information in said first and second instance identifier fields to extract said attribute instances from said first and second attribute field for said particular object instance, whereby said derived class inheriting said first attribute from said parent class of said class hierarchy is preserved in relational schema.

29. The apparatus of claim 25, wherein said abstract syntax notation is expressed in ASN.1 notation.

30. The apparatus of claim 25, further comprising means for generating a source code routine for creating a set of dictionary tables which contain information adequate to define the class hierarchy relationship.

31. The apparatus of claim 25, wherein said first and second table means automatically are operable generating source code routines for constructing SQL commands to create said first and second table structures, respectively;

and further comprising a relational database management system stored in a persistent memory of said second computer and means for sending said SQL commands to said relational database management system to cause said table structures to be generated and stored in said persistent memory.

32. The apparatus of claim 25, further comprising means for generating a source code routine to create a view of said second table structure which includes a join into said first table structure.

33. The apparatus of claim 25, further comprising means for generating a source code routine to create indexes on said table structure.

34. The apparatus of claim 25, wherein said schema compiler means further includes means for automatically providing additional source code routines for storage, deletion and retrieval of object instances in said table structures.