Method and system for object-based relational distributed databases

• US 5,724,575 A
• Filed: 07/01/1996
• Issued: 03/03/1998
• Est. Priority Date: 02/25/1994
• Status: Expired due to Term

• Current Assignee: WebMD Health Corporation
• Original Assignee: ActaMed Corp. (WebMD Health Corporation)
• Inventors: Daigle, Richard A., Miller, Barrick H., Schurenberg, Kurt, Hoover, Michael K.
• Primary Examiner(s): Heckler, Thomas M.
• Application Number:
  US08/674,024
• Time in Patent Office: 610 Days
• Field of Search: 395/610, 395/614, 395/615, 395/200.03, 395/200.09
• US Class Current: 1/1
• CPC Class Codes: G06F 16/245 Query processing
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor

Abstract

An object-based relational distributed database system and associated methods of operation that transforms data stored in a plurality of remote, heterogeneous user databases into a homogeneous data model is disclosed. Data stored in distributed, heterogeneous user database structures is homogenized by mapping into object attributes of predetermined instances of objects forming to a conceptual model that relates the various heterogeneous databases. The object attributes are stored in remote databases at client sites, which can be separate computer systems from the heterogeneous user databases or separate processes running on a computer system that maintains the heterogeneous user databases. The system stores location information and status information relating to the homogenized data in a centralized object broker for object management, thereby facilitating location and retrieval of data items from one or more of the remote, heterogeneous user databases.

Claims

1. A method of operating a distributed data processing system including a plurality of remotely located user computers that process user data in user databases and at least one object broker computer,

the user computers being interconnected with the object broker computer via a data communication network,

the user computers being operative to perform data processing operations upon user data in response to user commands, comprising the steps of:

(a) creating an object instance by assigning a unique object identifier to data items associated with a particular subject;

(b) storing the data items associated with the subject at the user computer in association with the object identifier;

(c) at the object broker computer, storing the locations of the user computers in a mapping table in association with object identifiers;

(d) associating a selected object identifier with data items stored in each of a plurality of user computers, some of the data items associated with the selected object identifier at a first one of the plurality of user computers being different from corresponding data items associated with the selected object identifier at a second one of the plurality of user computers;

(e) in response to a query to the object broker computer for data relating to the particular subject, retrieving the selected object identifier;

(f) in response to retrieval of an object identifier for the subject in the preceding step, retrieving the location of a selected one of the plurality of user computers associated with the selected object identifier; and

(g) retrieving data stored at the selected one of the plurality of user computers associated with the selected object identifier via the data communication network.

2. The method of claim 1, wherein each of the remotely located user computers comprises a heterogeneous data structure, and further comprising the steps of:

at the user computers, mapping predetermined data items stored in the user computers to corresponding object attributes associated with a predetermined instance of an object;

storing the object attributes in an object attribute table in the remote user computers in association with object identifiers.

3. The method of claim 1, wherein the query to the object broker originates at a first user computer, and the data associated with the selected object identifier is stored at a second user computer, and further comprising the step of communicating data retrieved, associated with the selected object identifier, to the object broker and then to the first user computer via the data communication network.

4. The method of claim 1, wherein the data items associated with the subject stored at the user computer in association with the object identifier are stored in an object attribute table.

5. The method of claim 4, wherein the remotely located user computers include at least one customer database and at least one remote database associated therewith, and wherein the object attribute table is stored in the remote database.

6. The method of claim 1, wherein the step of assigning a unique object identifier to data items associated with a subject comprises the steps of:

providing a global object identification address space corresponding to a range of object identifiers for association with a plurality of subjects;

allocating a predetermined range of object identifiers within the global object identification address space to each remotely located user computer.

7. The method of claim 6, wherein the step of allocating a predetermined range of object identifiers is carried out at the object broker computer, and wherein a new object instance is created by assigning a unique object identifier from a predetermined range of object identifiers is carried out at the user computers.

8. The method of claim 1, further comprising the step of maintaining an object index table at the object broker computer for relating at least one predetermined search term to at least one object identifier.

9. The method of claim 8, wherein the object index table for relating at least one predetermined search term to at least one object identifier is a relational base table, and further comprising the step of maintaining a junction index table relating object identifiers corresponding to a first class of objects to object identifiers corresponding to a second class of objects.

10. The method of claim 1, wherein the mapping table stores information relating object identifiers, status information, and location information.

11. The method of claim 10, wherein the step of retrieving the location of a selected one of the plurality of user computers associated with the selected object identifier comprises determining from the status information which one of the plurality of user computers contains the most current data items associated with the selected object identifier;

and

wherein the step of retrieving data stored at the selected one of the user computers associated with the selected object identifier via the data communication network comprises retrieving data stored at the user computer containing the most current data items associated with the selected object identifier.

12. The method of claim 10, wherein the user computers are located at a user computer site including at least one customer database and at least one remote database associated therewith, and wherein the location information relates to a data communications location for a remote database that stores data items in association with object identifiers.

13. The method of claim 12, wherein data items comprise at least one object attribute stored in at least one object attribute table maintained in the at least one remote database, and wherein the location information comprises information identifying at least one object attribute table in at least one remote database.

14. The method of claim 13, wherein the status information comprises date information identifying which one of a possible pluralities of occurrences of a selected object identifier is the most current.

15. The method of claim 1, wherein the user computers are located at a user computer site including at least one customer database and at least one remote database associated therewith, the at least one remote database storing an object attribute table for relating data items comprising object attributes to object identifiers, and wherein the object broker computer stores an object index table for relating at least one predetermined search term to at least one object identifier.

16. The method of claim 15, further comprising the steps of:

in response to an add request at one of the user computers to add a subject to the system, providing selected data items associated with the subject to be added from the customer database to the remote database;

at the remote database, carrying out the step of creating new object instance by assigning a new object identifier to data items associated with the subject;

communicating information relating the new object identifier to at least one corresponding search term to the object broker computer;

at the object broker computer, updating the object index table to reflect the association of the new object identifier with the corresponding search term;

at the object broker computer, updating the mapping table to reflect the location of the user computer that added the new object instance identified by the new object identifier.

17. The method of claim 15, further comprising the steps of:

in response to a search request at a querying one of the user computers to determine whether an object exists corresponding to a selected search term, communicating the selected search term to the object broker computer;

at the object broker computer, consulting the object index table to determine whether there is an object identifier associated with the selected search term;

in response to a determination that there is an object identifier associated with the selected search term, retrieving the corresponding object identifier;

providing a message to the querying user computer via the data communication network including the corresponding object identifier.

18. The method of claim 15, further comprising the steps of:

in response to a get request at a requesting one of the user computers based on a particular object identifier, communicating the particular object identifier to the object broker computer;

at the object broker computer, consulting the mapping table based on the particular object identifier to identify a particular remote database at a particular user computer site;

communicating a get message to the particular remote database at the particular user computer site including the particular object identifier;

at the particular remote database, consulting an object attribute table index to obtain retrieval information corresponding to the particular object identifier in the particular object attribute table;

retrieving object attributes associated with the particular object identifier from the particular object attribute table; and

communicating retrieved object attributes to the object broker computer and thence to the requesting user computer.

19. The method of claim 15, further comprising the steps of:

in response to a get all request at a requesting one of the user computers based on a particular object identifier that is related to one or more related object identifiers, communicating the particular object identifier to the object broker computer;

at the object broker computer, consulting an object index table that relates object identifiers of a first type to object identifiers of a second type to retrieve one or more related object identifiers associated with the particular object identifier;

at the object broker computer, consulting the mapping table based on retrieved related object identifiers to identify a one or more object attribute tables at one or more particular remote databases at one or more user computer sites containing data on the related object identifiers;

communicating a get message to the one or more remote databases including the related object identifiers;

at the one or more particular remote databases, consulting one or more object attribute table indexes to obtain retrieval information corresponding to the related object identifiers in the one or more object attribute tables;

retrieving object attributes associated with the related object identifiers from the one or more object attribute tables; and

communicating retrieved object attributes to the object broker computer and thence to the requesting user computer.

20. The method of claim 15, further comprising the steps of:

in response to an update request at an updating one of the user computers based on a particular object identifier for which one or more object attributes are to be updated, communicating the particular object identifier to the object broker computer together with the one or more object attributes to be updated;

at the object broker computer, consulting the mapping table based the particular object identifier to identify an object attribute table at a particular remote database at a user computer site containing the most current data corresponding to the particular object identifier;

communicating a get message to the particular remote database including the particular object identifier;

at the particular remote database, consulting an object attribute table index to obtain retrieval information corresponding to the particular object identifier in the object attribute table;

retrieving object attributes associated with the particular object identifier from the object attribute table;

communicating retrieved object attributes to the object broker computer;

at the object broker computer, updating the retrieved object attributes with the one or more object attributes to be updated, to obtain updated object attributes associated with the particular object attribute;

communicating the updated object attributes to the updating user computer for storage in the associated remote database.

21. The method of claim 20, further comprising the step of updating the mapping table and object index tables at the object broker computer to reflect that the updating user computer now has the most current information associated with the particular object identifier.

22. The method of claim 20, wherein the updating user computer is the same as the particular remote database containing the most current data corresponding to the particular object identifier.

23. The method of claim 20, wherein the remote database at the updating user computer did previously contain object attributes associated with the particular object identifier in an object attribute table, and further comprising the step of updating selected updated object attributes in the object attribute table associated with the particular object identifier.

24. The method of claim 20, wherein the updating user computer is at a different user site as the particular remote database containing the most current data corresponding to the particular object identifier.

25. The method of claim 24, wherein the remote database at the updating user computer did not previously contain any object attributes associated with the particular object identifier, and further comprising the step of adding the updated object attributes to an object attribute table associated with the updating user computer in association with the particular object identifier.

26. The method of claim 1, wherein each of the user computers are located at a user computer site including at least one customer database and at least one remote database associated therewith.

27. The method of claim 26, wherein at least one customer database is a heterogeneous database structure relative to at least one other computer system in the distributed system, and wherein the at least one remote database is homogeneous relative to the object broker computer.

28. The method of claim 26, wherein the at least one customer database runs on a different computer system than a computer system that runs the at least one remote database.

29. The method of claim 26, wherein the at least one customer database runs on the same computer system as the at least one remote database.

30. The method of claim 26, wherein at least one user computer in the distributed data processing system includes a customer database of a first database structure, and at least one other user computer in the distributed data processing system includes a customer database of a second database structure different from the first database structure so that such database structures are heterogeneous.

31. The method of claim 26, wherein the remote database associated with each user computer site is operative for performing the steps of creating a new object instance, storing data items in association with the object identifier, and retrieving data stored at the remote user computer associated with an object identifier provided by the object broker computer.

32. The method of claim 31, wherein the remote database is further operative for communicating location information and related object identifiers to the object broker computer via the data communications network.

33. The method of claim 26, wherein the step of storing the data items associated with the subject at the user computer in association with the object identifier comprises the steps of:

importing data items from a customer database into an associated remote database as selected data attributes associated with a particular object identifier, and

communicating the particular object identifier to the object broker computer.

34. The method of claim 33, wherein the step of communicating the particular object identifier to the object broker computer includes communicating predetermined search terms associated with the selected data attributes to the object broker computer.

35. The method of claim 34, further comprising the step of storing the predetermined search terms in an object attribute index stored at the object broker computer, the object attribute index relating object identifiers and search terms, and storing location information and status information indicative of the source and status of the object attributes and the object identifier in the mapping table.

36. The method of claim 33, wherein the step of importing data items from the customer database comprises the steps of:

importing a first set of data items from the customer database as object attributes associated with a first object identifier;

determining that the first object identifier is related to at least one additional second object identifier; and

importing a second set of data items from the customer database as object attributes associated with the second object identifier.

37. The method of claim 36, wherein the steps of importing comprise importing object attributes associated with the second object identifier that are in a dependent relationship to object attributes associated with the first object identifier in a predetermined order so as to preserve dependency relationships.

38. The method of claim 36, further comprising the steps of:

storing object attributes associated with the first object identifier in a first object attribute table;

storing the first object identifier and the second object identifier in a junction table relating object identifiers to each other;

storing object attributes associated with the second object identifier in a second object attribute table;

in response to a determination that the storing of object attributes for the second object identifier calls for information corresponding to the first object identifier, storing the first object identifier in a corresponding field in the second object attribute table,

whereby reference to the second object identifier causes referral to the first object identifier for selected object attributes.

39. The method of claim 26, wherein each remote database at each user computer site comprises a homogeneous data structure, and further comprising the step of importing selected data items from an associated customer database into the remote database.

40. The method of claim 39, wherein the step of importing selected data items from an associated customer database into the remote database comprises the step of mapping data items in a heterogeneous data structure on a customer database into predetermined object attributes stored in the associated remote database.

41. The method of claim 40, wherein the step of importing occurs in response to a put request message provided by a user at a user computer site.

42. The method of claim 40, wherein the step of importing comprises entering data items from the heterogeneous data structure into an object attribute table maintained at the associated remote database.

43. The method of claim 42, further comprising the step of maintaining an object attribute table index at the remote database to allow rapid searching for particular object attributes stored in an object attribute table in the respective remote database.

44. The method of claim 43, wherein the object attribute table index comprises a table relating an object identifier to one or more data items associated with the object identifier.

45. A method of operating a distributed data processing system including a plurality of independent remotely located user computers that process user data in user databases and at least one central computer,

the user computers being interconnected with the central computer via a data communication network,

the user computers being operative to perform data processing operations upon user data items in response to user commands, comprising the steps of:

(a) determining a set of objects, each object comprising a predetermined collection of attributes relating to a subject, each of the attributes comprising a data item;

(b) for a subject at one of the user computers for which data is to be processed in the system, creating an object instance by assigning a unique object identifier to data items associated with the subject;

(c) for the object, storing the attributes associated with the subject at the user computer in association with the object identifier in an object attribute table, the object attribute table being identified by an object attribute table identifier;

(d) transmitting a data message from the user computer that created the object to the central computer comprising the object identifier and the object attribute table identifier associated with the object;

(e) at the central computer, storing the locations of the user computers in a mapping table in association with object identifiers and the object attribute table identifiers;

(f) at the central computer, providing an index table relating the object identifiers to at least one predetermined search term, each search term comprising at least one data item associated with objects;

(g) in response to a query to the central computer for data relating to a particular subject in question, consulting the index table to retrieve an object identifier for the subject in question;

(h) in response to retrieval of an object identifier for the subject in question in the preceding step, retrieving the location of a remote user computer associated with the retrieved object identifier from the mapping table; and

(i) retrieving data stored at the remote user computer associated with the object identifier.

46. The method of claim 45, wherein the step of retrieving the location of a remote user computer associated with the retrieved object identifier from the mapping table comprises retrieving an object attribute table identifier that identifies a particular object attribute table in a particular user computer containing data items associated with the retrieved object identifier.

47. The method of claim 46, wherein the step of retrieving data stored at the remote user computer associated with the object identifier comprises retrieving data items associated with the retrieved object identifier stored in the particular object attribute table in the particular user computer.

48. A method of operating a distributed data processing system including a plurality of remotely located user computers that process user data and at least one central computer,

the user computers being interconnected with the central computer via a data communication network,

the user computers being operative to perform data processing operations in response to user commands, comprising the steps of:

(a) maintaining a mapping table in the central computer, the mapping table comprising a plurality of map table entries, each map table entry comprising object identifiers, location information, and status information associated with at least one data item stored in at least one of the user computers;

(b) in response to a query for information relating to a queried data item from a user at a querying one of the user computers, transmitting a query message from the querying user computer to the central computer via the data communication network, the query message including an object identifier associated with the queried data item;

(c) receiving the query message at the central computer;

(d) at the central computer, retrieving any stored map table entries from the mapping table corresponding to the object identifier associated with the queried data item;

(e) evaluating in accordance with predetermined status criteria the status information for the retrieved map table entries and determining the location of a selected one of a plurality of user computers having selected information stored therein concerning the queried data item;

(f) using the determined location, transmitting a get message including the object identifier associated with the queried data item from the central computer to the selected user computer via the data communication network;

(g) in response to the get message at the selected user computer, retrieving the selected information associated with the object identifier associated with the queried data item;

(h) transmitting the retrieved selected information to the central computer from the selected user computer via the data communications network; and

(i) upon receipt of the retrieved selected information at the central computer from the selected user computer, transmitting the retrieved selected information to the querying user computer via the data communications network.

49. The method of claim 48, wherein the predetermined status criteria is that of the most current information associated with the object identifier.

50. A method of operating a distributed data processing system including a plurality of remotely located user computers and at least one central computer,

the user computers being interconnected with the central computer via a data communication network,

comprising the steps of:

(a) at a first user computer, associating a particular object identifier with selected data items;

(b) transmitting the particular object identifier from the first user computer to the central computer via the data communication network;

(c) at a second user computer, associating the particular object identifier with different selected data items;

(d) transmitting the particular object identifier from the second user computer to the central computer via the data communication network; and

(e) at the central computer, storing the particular object identifiers from the first user computer and from the second user computer as plural map table entries in a mapping table, each of the map table entries including location information corresponding to the location of the first user computer and of the second user computer, and status information relating to the selected data items.

51. The method of claim 50, wherein a query from one of the user computers to the central computer results in retrieval of the plural map table entries, and retrieval of selected data items corresponding to the particular object identifier results in retrieval of a plurality of selected data items that differ by virtue of the status information.

52. The method of claim 50, further comprising the step of providing an application program interface (API) between the user databases and the central computer, for associating the object identifiers with the selected data items at the user databases, and transmitting the object identifiers and status information to the central computer for storage in the map table.

53. The method of claim 52, wherein the user computers are heterogeneous databases.

54. The method of claim 52, wherein the API is a computer program that runs on the user computer and is operative to interface with the user database.

55. The method of claim 54, wherein the API is a separate, second computer system that is located proximate to and communicates with the user computer, and includes the data communication hardware to the central computer.

56. A method of operating a distributed data processing system including a plurality of remotely located user computers that process user data in user databases,

the user computers being interconnected via a data communication network,

comprising the steps of:

(a) maintaining an object location service for associating object identifiers with search terms, object attribute table identifiers corresponding to object attribute tables located at user computers, and locations of user computers storing object attribute tables corresponding to object attribute table identifiers;

(b) at a selected user computer, associating a particular object identifier with a selected set of user data items;

(c) storing the selected set of user data items in a selected object attribute table at the selected user computer, the selected object attribute table being identified by a selected object attribute table identifier;

(d) transmitting the particular object identifier, a selected search term associated with the object identifier, and the object attribute table identifier to the location service via the data communication network; and

(e) at the location service, storing the particular object identifier, the selected search term, the selected object attribute table identifier, and location information.

57. The method of claim 56, wherein the location service comprises a map table for storing location information, status information, in association with object identifiers, and an object index for storing search terms in association with object identifiers.

58. The method of claim 56, wherein the location service is maintained at a central computer remotely located from the user computers.

59. The method of claim 56, wherein the user computers comprise a customer database and a remote database, and wherein the customer database comprises a heterogeneous data structure from other computers in the distributed system, and wherein the remote data base carries out operations for transforming data items in the heterogeneous data structure into a homogeneous data structure.

60. The method of claim 59, further comprising the step of importing data items from the heterogeneous data structure into the remote database.

61. The method of claim 59, wherein the customer database operates on the same computer system as the remote database.

62. The method of claim 59, wherein the customer database operates on a computer system different than a computer system on which the remote database operates, and further including the step of communicating data items between the customer database and the remote database.

63. A method of operating a distributed data processing system including a plurality of remotely located user computers that process user data in user databases and at least one central computer,

the user computers being interconnected with the central computer via a data communication network,

comprising the steps of:

(a) maintaining at the central computer an object index associating object identifiers with search terms;

(b) maintaining at the central computer a map table associating object identifiers with object attribute table identifiers corresponding to object attribute tables located at user computers, and locations of user computers storing object attribute tables corresponding to object attribute table identifiers;

(c) at a computer associated with a selected user computer, associating a particular object identifier with a selected set of user data items in the selected user computer;

(d) storing the selected set of user data items in a selected object attribute table at the selected user computer, the selected object attribute table being identified by a selected object attribute table identifier;

(e) transmitting the particular object identifier, a selected search term associated with the object identifier, and the object attribute table identifier to the central computer via the data communication network; and

(f) at the central computer, storing the particular object identifier and the selected search term in the object index, and the selected object attribute table identifier and location information in the map table.

64. The method of claim 63, further comprising the step of maintaining at the central computer a map table relating entry in a mapping table, the map table entry including location information corresponding to the location of the indexed selected user computer and status information relating to the indexed selected user data item.

65. The method of claim 63, wherein the user computers comprise a customer database and a remote database, and wherein the customer database comprises a heterogeneous data structure from other computers in the distributed system, and wherein the remote data base carries out operations for transforming data items in the heterogeneous data structure into a homogeneous data structure.

66. The method of claim 65, further comprising the step of importing data items from the heterogeneous data structure into the remote database.

67. The method of claim 65, wherein the customer database operates on the same computer system as the remote database.

68. The method of claim 65, wherein the customer database operates on a computer system different than a computer system on which the remote database operates, and further including the step of communicating data items between the customer database and the remote database.

69. A method of operating a distributed data processing system including a plurality of remotely located user computers that process user data in user databases,

the user computers being interconnected via a data communication network,

comprising the steps of:

(a) associating the same predetermined object identifier with a selected subset of data items stored in each of a plurality of user computers, the selected subset of data items in each of the plurality of user computers corresponding to the same logical object,

a selected subset of data items associated with a selected object identifier stored at a first user computer being more current than a corresponding subset of data items associated with the same object identifier at a second user computer as indicated by status information;

(b) providing a location service storing information relating object identifiers, location information, and status information associated with subsets of data items stored in the plurality of user computers;

(c) in response to a request for information relating to a particular logical object from a user at a requesting one of the user computers, searching an object index based on a selected search term to obtain at least one selected object identifier;

(d) consulting the location service based on the selected object identifier to obtain status information;

(e) examining the status information and the location information to determine a selected location of a selected user computer storing the most current data items associated with the selected object identifier;

(f) retrieving selected data items from the selected user computer; and

(g) transmitting the retrieved selected data items from the selected user computer to the requesting one of the user computers.

70. The method of claim 69, wherein the location service comprises a map table maintained a central computer connected for data communications with each of the plurality of remote user computers.

71. The method of claim 70, wherein the step of examining the status information and the location information occurs at the central computer, and further comprising the steps of:

communicating a get message from the central computer to the selected user computer via the data communication network;

at the selected user computer, retrieving the selected data items associated with the selected object identifier;

transmitting the retrieved selected data items to the central computer from the selected user computer via the data communications network;

upon receipt of the retrieved selected data items by the central computer from the selected user computer, transmitting the retrieved selected data items to the requesting user computer via the data communications network.

72. The method of claim 69, wherein the user computers comprise a customer database and a remote database, and wherein the customer database comprises a heterogeneous data structure from other computers in the distributed system, and wherein the remote data base carries out operations for transforming data items in the heterogeneous data structure into a homogeneous data structure.

73. The method of claim 72, further comprising the step of importing data items from the heterogeneous data structure into the remote database.

74. The method of claim 72, wherein the customer database operates on the same computer system as the remote database.

75. The method of claim 72, wherein the customer database operates on a computer system different than a computer system on which the remote database operates, and further including the step of communicating data items between the customer database and the remote database.

76. A method of operating a distributed data processing system including a plurality of remotely located user computers that store user data in heterogeneous user databases,

the user computers being interconnected via a data communication network,

comprising the steps of:

(a) determining a selected subset of heterogeneous user data items at one of the user computers corresponding to a predetermined logical object;

(b) homogenizing the selected subset of heterogeneous user data items to obtain homogenized data items by associating at least portions of the user data items with a predetermined object identifier related to the predetermined logical object;

(c) maintaining an index relating search terms to object identifiers associated with logical objects with; and

(d) maintaining a map table relating object identifiers with location information indicative of the location of each user computer that stores homogenized data items in association with object identifiers.

77. The method of claim 76, wherein the steps of maintaining the search index and the map table are carried out at a central computer that is connected to each of the user computers via the data communications network.

78. The method of claim 76, wherein the step of homogenizing the selected subset of heterogeneous user data items to obtain homogenized data items is carried out at the user computer site.

79. The method of claim 78, wherein the step of homogenizing is carried out in a computer system independent of the user computer but located at the user computer site.

80. A method of operating a distributed computing system including a plurality of remotely located user computers that store user data items, comprising the steps of:

providing a location service storing information relating to object identifiers, location information relating to locations of remotely located user computers where attributes of objects associated with object identifiers are stored, and status information relating to the currency of object attributes, where object attributes comprise user data items;

providing at least one object index relating predetermined search terms to object identifiers;

at a requesting computer, providing a selected search term for locating an object;

searching the object index based on the selected search term to determine whether an object identifier is associated with the selected search term;

in response to a determination in the preceding step that an object identifier is associated with the selected search term, retrieving a selected object identifier associated with the selected search term from the location service;

retrieving status information from the location service based on the selected object identifier;

utilizing the status information, determining selected location information from the location service indicative of the most current information for selected object attributes associated with the selected object identifier;

initiating a communication to a user computer associated with the selected location information to retrieve the selected object attributes associated with the selected object identifier; and

transmitting the selected object attributes to the requesting computer.

81. The method of claim 80, wherein the requesting computer comprises one of the remotely located user computers.

82. The method of claim 80, wherein the requesting computer comprises a stand alone personal computer system connected for data communications with the location service.

83. The method of claim 80, wherein the location service comprises a map table for storing location information, status information, in association with object identifiers, and an object index for storing search terms in association with object identifiers.

84. The method of claim 83, wherein the map table is maintained in a central object broker computer.

85. The method of claim 84, wherein the object broker computer is operative to maintain the object index.

86. A method of operating a distributed data processing system including a plurality of remotely located user computers,

the user computers being interconnected for data communications via a data communication network, comprising the steps of:

(a) providing a location service storing information relating object identifiers and location information associated with data items stored in a plurality of user computers;

(b) providing a first object identifier in association with data items relating to a first logical object;

(c) providing at least one second object identifier in association with data items relating to at least one second logical object;

(d) providing an object index table for associating the first logical object with at least one second logical object by storing the first object identifier in association with at least one second object identifier;

(e) in response to a request for information relating to the first logical object originating at one of the user computer, searching the object index table based on the first object identifier to obtain at least one selected second object identifier associated with at least one second logical object;

(f) consulting the location service based on the at least one selected second object identifier to obtain the location of a selected user computer storing data items associated with the at least one selected second object identifier; and

(g) retrieving data items associated with the at least one second object identifier from the selected user computer.

87. The method of claim 86, wherein the distributed data processing system includes at least one central computer operative for providing the location service, the object index table, and issuing requests to user computers to retrieve data items corresponding to object identifiers.

88. The method of claim 86, wherein the object index table comprises a junction table comprising a plurality of entries associating the first object identifier with a plurality of second object identifiers.

89. The method of claim 86, wherein the object index table is searchable by any object identifier.

90. A method of operating a distributed data processing system including a plurality of remotely located user computers,

the user computers being interconnected for data communications via a data communication network, comprising the steps of:

(a) providing a location service storing information relating object identifiers and location information associated with data items stored in a plurality of user computers;

(b) providing a plurality of types of object identifiers, each object identifier being associated with data items relating to a logical object of a predetermined type;

(c) providing an object index table for associating logical objects by storing object identifiers of one type in association with object identifiers of a different type;

(d) in response to a request for information relating to a particular logical object of a first type originating at one of the user computers, searching the object index table based on the object identifier of the particular logical object to obtain one or more selected object identifiers of a second type associated with one or more second logical objects;

(e) consulting the location service based on the one or more selected object identifiers of the second type to obtain the location of one or more selected user computers storing data items associated with the one or more selected object identifiers of the second type; and

(f) retrieving data items associated with the one or more selected object identifiers of the second type from the one or more selected user computers.

91. The method of claim 90, wherein the object index table comprises data relating at least one object identifier of a first type to multiple object identifers of a second type, and data relating at least one object identifier of the second type to multiple object identifers of the first type.

92. The method of claim 90, wherein the distributed data processing system includes at least one central computer operative for providing the location service, the object index table, and issuing requests to user computers to retrieve data items corresponding to object identifiers.

93. The method of claim 90, wherein the object index table comprises a junction table comprising a plurality of entries associating the first object identifier with a plurality of second object identifiers.

94. The method of claim 90, wherein the object index table is searchable by any object identifier.

95. A method of operating a distributed data processing system including a plurality of remotely located user computers and at least one central computer,

the user computers being interconnected with the central computer via a data communication network, comprising the steps of:

(a) providing an object attribute table in at least one of the user computers for storing data items in association with object identifiers;

(b) providing an object index table at the central computer for associating predetermined search information to object identifiers;

(c) providing a mapping table at the central computer for storing locations of the user computers and object attribute tables at the user computers in association with object identifiers;

(d) assigning a selected object identifier to data items associated with a particular subject;

(e) storing the data items associated with the particular subject in association with the selected object identifier at a particular user computer;

(f) in response to a query to the central computer for data relating to the particular subject, utilizing the predetermined search information in the object index table to retrieve the selected object identifier associated with the subject;

(g) utilizing the selected object identifier, determining from the mapping table the location of the particular user computer and an object attribute table at the particular user computer;

(h) retrieving data items associated with the selected object identifier that are stored in the object attribute table at the particular user computer via the data communication network.

96. A distributed computer system, comprising:

a plurality of remotely located user computers, each of the user computers being operative to perform data processing operations in response to user commands;

at least one central computer;

a data communication network connecting the user computers with the central computer;

each of the user computers being operative for;

storing data items in association with an object identifier; and

transmitting said object identifier to said central computer;

the central computer being operative for storing object identifiers received from the user computers in association with information indicating the location of the user computers; and

the central computer being operative for storing plural instances of a particular object identifier associated with data items stored in each of a plurality of user computers, some of the data items associated with the particular object identifier at a first one of the plurality of user computers being different from corresponding data items associated with the particular object identifier at a second one of the plurality of user computers.

97. The distributed computer system of claim 96, further comprising an object attribute index stored at said central computer, said object attribute index relating object identifiers and search terms, and a mapping table stored at said central computer, said mapping table storing location information and status information indicative of the source and status of the object attributes, and said object identifiers.

98. The distributed computer system of claim 96, wherein said central computer is operative in response to a request for information relating to a particular subject, for determining, from said plural instances of said particular object identifier, which data items at which of said plurality of user computers is most current.

99. The distributed computer system of claim 96, further comprising a mapping table stored at said central computer for storing object identifiers received from said user computers in association with information indicating the location of said user computers, and for storing status information.

100. The distributed computer system of claim 99, wherein said status information indicates which of said plural instances of a particular object identifier associated with data items stored in each of said plurality of user computers is most current.

101. The distributed computer system of claim 96, wherein said central computer is operative in response to a request for information relating to a particular subject from a requesting one of said user computers via said data communication network for:

determining a selected object identifier associated with said particular subject;

determining a selected one of said user computers in which data associated with said selected object identifier is stored;

transmitting via said data communication network a request for information to said selected one of said user computers, said request including said selected object identifier.

102. The distributed computer system of claim 101, wherein said selected one of said user computers is operative, in response to receipt of said request for information, for:

retrieving a data item associated with said selected object identifier; and

transmitting said retrieved data item to said central computer via said data communication network.

103. The distributed computer system of claim 102, wherein said central computer is operative, in response to a receipt of said retrieved data item, for transmitting said retrieved data item to said requesting one of said user computers via said data communication network.

104. The distributed computer system of claim 96, wherein each of said user computers is operative for:

storing said data items in association with said object identifier in an object attribute table identified by an object attribute table identifier, and

communicating said object attribute table identifier and object identifier to said central computer.

105. The distributed computer system of claim 104, further comprising an object attribute table index stored at a user computer to allow rapid searching for particular object attributes stored in an object attribute table in said user computer.

106. The distributed computer system of claim 105, wherein said object attribute table index comprises a table relating an object identifier to one or more data items associated with said object identifier.

107. The distributed computer system of claim 106, wherein said user computer site is operative for creating a new object instance, storing data items in association with the object identifier, and retrieving data stored at user associated with an object identifier provided by central computer.

108. The distributed computer system of claim 96, wherein each of said user computers is located at a user computer site including at least one customer database and at least one remote database associated therewith, wherein at least one customer database comprises a database structure that is heterogeneous relative to at least one other computer system in the distributed computer system, and wherein said at least one remote database comprises a database structure that is homogeneous relative to the central computer.

109. The distributed computer system of claim 108, wherein the at least one customer database runs on a different computer system than a computer system that runs the at least one remote database.

110. The distributed computer system of claim 108, wherein the at least one customer database runs on the same computer system as the at least one remote database.

111. The distributed computer system of claim 108, wherein at least one user computer in said distributed computer system includes a customer database comprising a first database structure, and at least one other user computer in said distributed computer system includes a customer database comprising a second database structure different from said first database structure so that such database structures are heterogeneous.

112. The distributed computer system of claim 108, wherein said remote database is further operative for communicating location information and related object identifiers to said central computer via said data communications network.

113. The distributed computer system of claim 108, wherein said user computers are operative for:

importing data items from a customer database into an associated remote database as selected data attributes associated with a particular object identifier, and

communicating said particular object identifier to said central computer.

114. The distributed computer system of claim 113, wherein the step of importing data items from the customer database comprises the steps of:

importing a first set of data items from the customer database as object attributes associated with a first object identifier;

determining that the first object identifier is related to at least one additional second object identifier; and

importing a second set of data items from the customer database as object attributes associated with the second object identifier.

115. The distributed computer system of claim 108, wherein each remote database at each user computer site comprises a homogeneous data structure, and further comprising the step of importing selected data items from an associated customer database into the remote database.

116. The distributed computer system of claim 115, wherein the step of importing selected data items from an associated customer database into the remote database comprises the step of mapping data items in a heterogeneous data structure on a customer database into predetermined object attributes stored in the associated remote database.

117. The distributed computer system of claim 116, wherein the step of importing comprises entering data items from the heterogeneous data structure into an object attribute table maintained at the associated remote database.

118. A distributed data processing system, comprising:

a plurality of remotely located user computers;

at least one central computer;

a data communication network connecting the user computers with the central computer;

an object attribute table stored in at least one of the user computers for storing data items in association with object identifiers;

an object index table at the central computer for associating predetermined search information to object identifiers;

a mapping table at the central computer for storing locations of the user computers and object attribute tables at the user computers in association with object identifiers;

a user computer being operative for;

assigning a selected object identifier to data items associated with a particular subject; and

storing the data items associated with the particular subject in association with the selected object identifier;

the central computer being operative in response to a query for data relating to the particular subject for;

utilizing the predetermined search information in the object index table to retrieve the selected object identifier associated with the subject;

utilizing the selected object identifier, determining from the mapping table the location of a particular user computer storing data items associated with the particular subject and the identity of a particular object attribute table at the particular user computer in which said data items are stored; and

retrieving data items associated with the selected object identifier that are stored in the particular object attribute table at the particular user computer via the data communication network.