Method of recursive objects for representing hierarchies in relational database systems

• US 20040083222A1
• Filed: 05/02/2003
• Published: 04/29/2004
• Est. Priority Date: 05/09/2002
• Status: Active Grant

• Current Assignee: Robert Pecherer
• Original Assignee: Robert Pecherer
• Inventors: Pecherer, Robert
• Granted Patent: US 7,548,935 B2
• Time in Patent Office: Days
• US Class Current: 707/100
• CPC Class Codes: G06F 16/284 Relational databases
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure

Abstract

A method is described for creating and managing a two-level hierarchical data structure. Parent and child object relation tables, an aggregate relation table and a link relation table having records are created wherein each link relation record has an aggregate identity field and a child object identity field and the aggregate relation records have a parent object identity field pointing to a parent object relation record. The link relation records have an aggregate identity field pointing to an aggregate relation record and to a child object relation record whereby zero or more child object relation records are linked to a parent object record relation record.

Claims

1. A method of recursive objects for representing a two level hierarchy called an aggregate that associates one record of a first, parent class and zero or more records of a second, child class, each said class defined by the records of a relation within a relational database, comprising the steps of:

(a) defining an aggregate relation with a record schema including at least a first aggregate field to uniquely identify one aggregate record among all aggregate records in said aggregate relation, and a second aggregate field to uniquely identify one parent class record among all parent class records in said parent class relation;

(b) defining a link relation with a record schema including at least a first link field to uniquely identify one aggregate record among all aggregate records in said aggregate relation, and a second link field to uniquely identify one child class record among all child class records in said child class relation;

(c) representing said aggregate by

(i) storing one record in the aggregate relation with its unique identifier in said first aggregate field, and said second aggregate field set to the value of the unique identifier of one parent class record of said parent class relation;

(ii) for each of zero or more child records in said aggregate, storing one record in the link relation with said first link field set to the value of the unique identifier of said aggregate record, and said second link field set to the value of the unique identifier of a child class record of said child class relation;

(iii) whereby said aggregate will be represented by exactly one record in said aggregate relation uniquely identifying said parent class record, and by zero or more link records in said link relation uniquely identifying said child class record(s); and

(iv) whereby a two level hierarchy or aggregate associating one record of a first, parent class and zero or more records of a second, child class is accurately represented.

2. A two level hierarchy called an aggregate, associating one record of a first, parent class and zero or more records of a second, child class, each of said classes is being defined respectively by a parent class relation and a child class relation within a relational database, comprising:

(a) an aggregate relation whose aggregate relation record schema comprises;

(i) a single aggregate record among a set of aggregate records in said aggregate relation uniquely identified by data within said aggregate relation record schema;

(ii) a single parent class record among a set of parent class records in said parent class of said parent class relation uniquely identified by data within said aggregate relation record schema;

(b) a link relation within a link relation record schema including;

(i) a single aggregate record among the set of aggregate records in said aggregate relation uniquely identified by data within said link relation schema;

(ii) a single child class record of said class among all child class records in said child class relation uniquely identified by data within the link relation schema;

(c) representation data representing each aggregate by;

(i) storing one aggregate record in said aggregate relation uniquely identifying one parent class record among all parent class records within said parent class relation;

(ii) storing zero or more link records in said link relation, each of which link record uniquely identifies said aggregate record, and uniquely identifies one child class record among all records within said child class relation;

(iii) whereby each record of said aggregate is represented by exactly one record in said aggregate relation identifying said parent class record and zero or more records in said link relation, each identifying one child class record; and

(iv) whereby a two level hierarchy or aggregate associating one record of said first, parent class and zero or more records of said second, child will be accurately and unambiguously represented.

3. A method for creating and managing a two-level hierarchical data structure in at least one relational database management system (RDBMS), comprising the steps of:

(a) creating a parent object relation table in said RDBMS g a plurality of parent object relation records;

(b) creating a child object relation table in said RDBMS having a plurality of child object relation records;

(c) creating an aggregate relation table in said RDBMS having a plurality of aggregate relation records each having a parent object identity field;

(d) creating a link relation table in said RDBMS having zero or more link relation records, each link relation record having (i) an aggregate identity field and (ii) a child object identity field;

(e) said aggregate relation records having a parent object identity field pointing to a parent object relation record of said plurality of parent object relation records in said parent object relation table; and

(f) said link relation records having an aggregate identity field pointing to an aggregate relation record of said plurality of aggregate relation records in said aggregate relation table and to a child object relation record of said plurality of child object relation records in said child object relation table whereby zero or more child object relation records are linked to a parent object record relation record.

4. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 3, comprising the further steps of:

(a) providing a first link relation record of said plurality of link relation records having (i) a first aggregate identity field pointing to a first aggregate relation record of said plurality of aggregate relation records associated with a first parent object relation record of said plurality of parent object relation records, and (ii) a first child object identity field adapted to point to single child object relation record within said child object relation table; and

(b) providing a second link relation record of said plurality of link relation records differing from said first link relation record having (i) a second aggregate identity field pointing to a second aggregate relation record of said plurality of aggregation records associated with a second parent object relation record of said plurality of parent object relation records, and (ii) a second child object identity field adapted to point to a single child object relation record within said child object relation table.

5. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 4, comprising the further step of providing a first child object relation record within said child object relation table.

6. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 5, comprising the further steps of:

(a) pointing said first child object identity field of said first link relation record of said plurality of link relation records to said first child object relation record;

(b) pointing said second child object identity field of said second link relation record of said plurality of link relation records to said first child object relation record; and

(c) whereby said first child object relation record is linked to both said first parent object relation record and said second parent object relation record to provide a first linked child object relation record.

7. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 5, comprising the further steps of:

(a) providing a second child object relation record within said child object relation table;

(b) pointing said second child object identity field of said second link relation record of said plurality of link relation records to said second child object relation record; and

(c) whereby said first child object relation record is linked to said first parent object relation record and said second child object relation record is linked to said second parent object relation record.

8. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 7, wherein said second child object relation record is identical to said first child object relation record.

9. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 6, wherein said parent object relation table comprises a first schema having a first schema organization including a first key for identifying a parent object relation record of said parent object relation records.

10. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 9, wherein said child object relation table comprises a second schema having a second schema organization including a second key for identifying a first child object relation record of said child object relation table.

11. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 10, wherein said aggregate relation table comprises a third schema having a third schema organization including a third key for identifying an aggregate relation record of said plurality of aggregate relation records.

12. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 11, wherein said link relation table comprises a fourth schema having a fourth schema organization including a fourth key for identifying a link relation record of said plurality of link relation records.

13. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 12, comprising the further step of altering a relationship between a third parent object relation record of said plurality of parent object relation records and said first child object relation record independently of any changes to said third parent object relation record and independently of any changes to said first child object relation record.

14. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 13, comprising the further step of altering said relationship between said third parent object relation record and said first child object relation record by changing an aggregate identity field of a link relation record of said plurality of link relation records.

15. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 13, comprising the further step of altering said relationship between said third parent object relation record and said first child object relation record by changing a child object identity field of a link relation record of said plurality of link relation records.

16. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 13, comprising the further step of altering said relationship between said third parent object relation record and said first child object relation record by changing a parent object identity field of an aggregate relation record of said plurality of aggregate relation records.

17. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 6, comprising the further steps of:

(a) providing a plurality of child object relation records including therein a plurality of associated child object relation records, all associated child object relation records of said plurality of associated child object relation records being associated with a fourth parent object relation record; and

(b) determining said associated child object relation records within said plurality of associated child object relation records in accordance with said link relation table.

18. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 6, wherein said first child object relation record further comprises a child object identity field and (i) said first child identity field of said first link relation record, and (ii) said second child identity field of said second link relation record, both point to said child object identity field of said first child object relation record.

19. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 6, wherein said first and second aggregate relation records include respective first and second aggregate identity fields and said first aggregate identity field of said first link relation record points to said first aggregate identity field of said first aggregate relation record and said second aggregate identity field of said second link relation record points to said second aggregate identity field of said second aggregate relation record.

20. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 6, comprising the further steps of:

(a) providing fifth and sixth parent object relation records within said parent object relation table;

(b) providing a fifth child object relation record within said child object relation table;

(c) providing third and fourth aggregate relation records of said plurality of aggregate relation records having parent object identity fields pointing to said fifth and sixth parent object relation records respectively;

(d) providing third and fourth link relation records of said plurality of link relation records having (i) respective third and fourth aggregate identity fields pointing to said third and fourth aggregate relation records, and (ii) a third and fourth child object identity fields pointing to said third child object relation record; and

(e) whereby said third child object relation record is linked to said fifth and sixth parent object relation records to provide a second linked child object relation record in addition to said first linked child object relation record.

21. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 20, wherein said first and second parent object relation records linked to said first child object relation record and said fifth and sixth parent object relation records linked to said third child object relation record are mutually exclusive.

22. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 20, wherein said first and second parent object relation records comprise at least one of said third and fourth parent object relation records.

23. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 20, wherein said first child object relation record comprises said third child object relation record.

24. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 6, wherein said parent object relation table is disposed in a first RDBMS and said child object relation table is disposed in a second RDBMS.

25. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 6, comprising the further step of providing fifth and sixth aggregate relation records of said plurality of aggregate relation records having respective parent object identity fields both pointing to a seventh parent object relation record.

26. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 25, wherein said fifth and sixth aggregate relation records are linked to differing child object relation records of said plurality of child object relation records.

27. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 26, comprising the step of altering the relationships of said differing children to said seventh parent object relation record.

28. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 6, wherein the step of providing said first child object relation record comprises the step of inserting a link relation record into said link relation table.

29. The method for creating and managing a two-level hierarchical data structure in at least one relational database management system of claim 6, comprising the further steps of:

(a) providing an eighth parent object relation record of said plurality of parent object records;

(b) providing a fifth aggregate relation record of said plurality of aggregate relation records having a fifth parent object identity field pointing to said eighth object relation record;

(c) providing a fifth link relation record of said plurality of link relation records having;

(i) a fifth aggregate identity field pointing to said fifth aggregate relation record; and

(ii) a fifth child object identity field pointing to said first child object relation record whereby said first child object relation record is linked to said first, second and eighth parent object relation records.

30. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 6, further comprising the step of creating an object type descriptor table having object relation retrieval information for retrieving a selected object relation from a selected one of said parent object relation table and said child object relation table.

31. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 30, wherein said object relation retrieval information further comprises information for specifying a selected host relational server wherein said selected object relation is disposed within said selected relational server.

32. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 31, wherein said object relation retrieval information further comprises information for specifying a network address of said host selected relational server.

33. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 32, wherein said object relation retrieval information further comprises information for specifying a name of a relational database.

34. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 33, wherein said object relation retrieval information further comprises information for specifying a name of said selected object relation.

35. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 34, wherein said object relation retrieval information further comprises information for specifying whether said selected object relation is a parent object relation or a child object relation.

36. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 34, including first and second selected object relations wherein said parent object relation table and said child object relation table are disposed in differing relational databases.

37. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 30, wherein said object relation retrieval information further comprises information for specifying a type classification of said selected object relation.

38. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 30, comprising the further steps of:

(a) creating a link type relation table having a plurality of link types; and

(b) providing a link type pointer within a selected link relation record of said plurality of link relation records pointing to a link type of said plurality of link types for identifying a link type associated with said selected link relation record.

39. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 31, said aggregate type relation:

(a) a first aggregate relation specifying pointer for specifying a parent object type relation in said object type descriptor table;

(b) a second aggregate relation specifying pointer for specifying a child object type relation in said object type descriptor table; and

(c) a third aggregate relation specifying pointer for specifying a link type relation in said link type relation table.

40. A method for creating and managing a two-level hierarchical data structure in at least one relational database management system, comprising the steps of:

(a) creating an object relation table in said RDBMS having a plurality of object relation records, including a plurality of parent object relation records and zero or more child object relation records;

(b) creating an aggregate relation table in said RDBMS having a plurality of aggregate relation records;

(c) creating a link relation table in said RDBMS having a plurality of link relation records;

(d) said aggregate relation records having a parent object pointer pointing to a parent object relation record of said plurality of parent object relation records in said object relation table; and

(e) said link relation records having (i) a plurality of aggregate relation pointers pointing to aggregate relation records of said plurality of aggregate relation records in said aggregate relation table, and (ii) zero or more child object pointers adapted to point to a single child object relation record in said object relation table.

41. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 40, comprising the further steps of:

(a) creating an object type relation table having a plurality of object types; and

(b) providing an object type pointer within a selected object relation record of said plurality of object relation records pointing to an object type of said plurality of object types for identifying an object type associated with said selected object relation record.

42. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 41, comprising the further steps of:

(a) creating a link type relation table having a plurality of link types; and

(b) providing a link type pointer within a selected link relation record of said plurality of link relation records pointing to a link type of said plurality of link types for identifying a link type associated with said selected link relation record.

43. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 41, further comprising the steps of:

(a) creating an aggregate type relation table having a plurality of aggregate types; and

(b) providing an aggregate type pointer within a selected aggregate relation record of said plurality of aggregate relation records pointing to an aggregate type of said plurality of aggregate types for identifying an aggregate type associated with said selected aggregate relation record.

44. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 43, said aggregate type relation comprising:

(a) a first aggregate relation specifying pointer for specifying a parent object type relation in said object type descriptor table; and

(b) a second aggregate relation specifying pointer for specifying a child object type relation in said object type descriptor table.

45. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 41, comprising the further steps of:

(a) creating a link type table having a plurality of link types;

(b) providing a link type pointer within a selected link relation record of said plurality of link relation records pointing to a link type of said plurality of link types for identifying a link type associated with said selected link relation record;

(c) creating an aggregate type relation table having a plurality of aggregate types; and

(d) providing an aggregate type pointer within a selected aggregate relation record of said plurality of aggregate relation records pointing to an aggregate type of said plurality of aggregate types for identifying an aggregate type associated with said selected aggregate relation record.

46. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 45, said aggregate type relation comprising:

(a) a first aggregate relation specifying pointer for specifying a parent object type relation in said object type descriptor table;

(b) a second aggregate relation specifying pointer for specifying a child object type relation in said object type descriptor table; and

(c) a third aggregate relation specifying pointer for specifying a link type relation in said link type relation table.

47. A two-level hierarchical data structure in a relational database management system (RDBMS), comprising:

(a) a parent object relation table in said RDBMS having a plurality of parent object relation records;

(b) a child object relation table in said RDBMS adapted to receive a first child object relation record;

(c) an aggregate relation table in said RDBMS having a plurality of aggregate relation records each having a parent object identity field;

(d) a link relation table in said RDBMS having a plurality of link relation records each having (i) an aggregate identity field and (ii) a child object identity field;

(e) said aggregate relation records having a parent object identity field pointing to a parent object relation record in said parent object relation table;

(f) said link relation records having an aggregate identity field pointing to an aggregate of said aggregate relation records and a child object identity field pointing to a child object relation record;

48. The two-level hierarchical data structure in at least one relational database management system of claim 47, further comprising:

(a) a first link relation record of said plurality of link relation records having (i) a first aggregate identity field pointing to a first aggregate relation record of said plurality of aggregate relation records associated with a first parent object relation record of said plurality of parent object relation records, and (ii) a first child object identity field adapted to point to said single child object relation record within said child object relation table; and

(b) a second link relation record of said plurality of link relation records differing from said first aggregate relation record having (i) a second aggregate identity field pointing to a second aggregate relation record of said plurality of aggregation records associated with a second parent object relation record of said plurality of parent object relation records, and (ii) a second child object identity field adapted to point to said single child object relation record within said child object relation table.

49. The two-level hierarchical data structure in at least one relational database management system of claim 48, further comprising a first child object relation record within said child object relation table.

50. The two-level hierarchical data structure in at least one relational database management system of claim 49, further comprising:

(a) said first child object identity field of said first link relation record of said plurality of link relation records pointing to said first child object relation record;

(b) said second child object identity field of said second link relation record of said plurality of link relation records pointing to said first child object relation record; and

(c) whereby said first child object relation records is linked to said first parent object relation record and said second parent object relation record to provide a first linked object relation record.

51. The two-level hierarchical data structure in at least one relational database management system of claim 50, further comprising:

(a) a second child object relation record within said child object relation table;

(b) said second child object identity field of said second link relation record of said plurality of link relation records pointing to said second child object relation record; and

(c) whereby said first child object relation record is linked to said first parent object relation record and second child object relation record is recursively linked to said second parent object relation record.

52. The two-level hierarchical data structure in at least one relational database management system of claim 49, further comprising an altering of a relationship between a first selected parent object relation record of said plurality of object relation records and said first child object relation record provided independently of any changes to said selected parent object relation record and independently of any changes to said child object identity field.

53. The two-level hierarchical data structure in at least one relational database management system of claim 52, further comprising an altering of said relationship between said first selected parent object relation record and said first child object relation record provided by changing an aggregate identity field of a link relation record of said plurality of link relation records.

54. The two-level hierarchical data structure in at least one relational database management system of claim 53, further comprising an altering of said relationship between said first selected parent object relation record and said first child object relation record provided by changing a value of said third key.

55. The two-level hierarchical data structure in at least one relational database management system of claim 50, further comprising

(a) a plurality of child object relation records including therein a plurality of associated child object relation records, each associated child object relation record of said plurality of associated child object relation records being associated with a second selected parent object relation record;

and

(b) a determination of said associated child object relation records within said plurality of associated child object relation records in accordance with said link relation table.

56. The two-level hierarchical data structure in at least one relational database management system of claim 50, wherein said first child object relation record further comprises a child object identity field, and (i) said first child identity field of said first link relation record, and (ii) said second child identity field of said second link relation record both point to said child object identity field of said first child object relation record.

57. The two-level hierarchical data structure in at least one relational database management system of claim 49, wherein first and second aggregate relation records include respective first and second aggregate identity fields and said first aggregate identity field of said first link relation record points to said first aggregate identity field of said first aggregate relation record and said second aggregate identity field of said second link relation record points to said second aggregate relation identity field of said second aggregate relation record.

58. The two-level hierarchical data structure in at least one relational database management system of claim 48, further comprising:

(a) a fifth parent object relation record of said plurality of parent object relation records;

(b) a fifth aggregate relation record of said plurality of aggregate relation records having a fifth parent object identity field; and

(c) a fifth link relation record of said plurality of link relation records having (i) a fifth aggregate identity field pointing to said fifth aggregate relation record, and (ii) a fifth child object identity field pointing to said first child object relation record whereby said first child object relation record is linked to said first, second and third parent objection relation records.

59. The two-level hierarchical data structure in at least one relational database management system of claim 48, wherein said first child object relation table comprises said first parent object relation table, whereby said first link child object relation record and said first parent object relation record are included in a single object relation table.

60. The two-level hierarchical data structure in at least one relational database management system of claim 50, further comprising:

(a) an aggregate type relation table having a plurality of aggregate types;

(b) an aggregate type pointer within a selected aggregate relation record of said plurality of aggregate relation records pointing to an aggregate type of said plurality of aggregate types for identifying an aggregate type of said plurality of aggregate types associated with said selected aggregate relation record;

(c) an object type descriptor table having a plurality of object types having a plurality of parent object type pointers for pointing to a selected parent object relation record in said parent object relation table thereby providing a descriptor-indicated parent object relation record for identifying an object type of said plurality of object types associated with said descriptor-indicated parent object relation record; and

(d) said object type descriptor table having zero more child object type pointers for pointing to a selected child object relation record in said child object relation table thereby providing a descriptor-indicated child object relation record for identifying an object type of said plurality of object types associated with said descriptor-indicated child object relation record.

61. The two-level hierarchical data structure in at least one relational database management system of claim 58, further comprising:

(a) a link type relation table in said RDBMS having a plurality of link types; and

(b) a link type pointer within a selected link relation record of said plurality of link relation records pointing to a link type of said plurality of link types for identifying a link type associated with said selected link relation record.

62. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 60, said aggregate type relation comprising:

(a) a first aggregate relation specifying pointer for specifying a parent object type relation in said object type descriptor table;

(b) a second aggregate relation specifying pointer for specifying a child object type relation in said object type descriptor table; and

(c) a third aggregate relation specifying pointer for specifying a link type relation in said link type relation table.

63. A two-level hierarchical data structure in at least one relational database management system, comprising:

(a) an object relation table in said RDBMS having a plurality of object relation records, including a plurality of parent object relation records and zero or more child object relation records;

(b) an aggregate relation table in said RDBMS having a plurality of aggregate relation records;

(c) a link relation table in said RDBMS having a plurality of link relation records;

(d) said aggregate relation records having a parent object pointer pointing to a parent object relation record of said plurality of parent object relation records in said object relation table; and

(e) said link relation records having (i) a plurality of aggregate relation pointers pointing to aggregate relation records of said plurality of aggregate relation records in said aggregate relation table, and (ii) one or more child object pointers adapted to point to a single child object relation record in said object relation table.

64. The hierarchical data structure in at least one relational database management system of claim 63, further comprising:

(a) an object type relation table having a plurality of object types; and

(b) an object type pointer within a selected object relation record of said plurality of object relation records pointing to an object type of said plurality of object types for identifying an object type associated with said selected object relation record.

65. The hierarchical data structure in at least one relational database management system of claim 64, further comprising:

(a) a link type relation table having a plurality of link types;

(b) a link type pointer within a selected link relation record of said plurality of link relation records pointing to a link type of said plurality of link types for identifying a link type associated with said selected link relation record.

66. The hierarchical data structure in at least one relational database management system of claim 64, further comprising:

(a) an aggregate type relation table having a plurality of aggregate types; and

(b) an aggregate type pointer within a selected aggregate relation record of said plurality of aggregate relation records pointing to an aggregate type of said plurality of aggregate types for identifying an aggregate type associated with said selected aggregate relation record.

67. The hierarchical data structure in at least one relational database management system of claim 66, further comprising at least one additional pointer within a further selected aggregate relation record of said plurality of aggregate relation records pointing to an object type of said plurality of object types for identifying an object type associated with said further selected aggregate record.

68. The hierarchical data structure in at least one relational database management system of claim 64, further comprising

(a) a link type relation table having a plurality of link types;

and

(b) a link type pointer within a selected link relation record of said plurality of link relation records pointing to a link type of said plurality of link types for identifying a link type associated with said selected link relation record;

(c) an aggregate type relation table having a plurality of aggregate types; and

(d) an aggregate type pointer within a selected aggregate relation record of said plurality of aggregate relation records pointing to an aggregate type of said plurality of aggregate types for identifying an aggregate type associated with said selected aggregate relation record.

69. The method for creating and managing a hierarchical data structure in at least one relational database management system of claim 68, said aggregate type relation comprising:

(a) a first aggregate relation specifying pointer for specifying a parent object type relation in said object type descriptor table;

(b) a second aggregate relation specifying pointer for specifying a child object type relation in said object type descriptor table; and

(c) a third aggregate relation specifying pointer for specifying a link type relation in said link type relation table.