Mechanisms for storing content and properties of hierarchically organized resources

• US 7,047,253 B1
• Filed: 09/27/2002
• Issued: 05/16/2006
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Sedlar, Eric, Murthy, Ravi, Agarwal, Nipun, Jalali, Neema
• Primary Examiner(s): Mizrahi, Diane D.
• Application Number:
  US10/256,524
• Time in Patent Office: 1,327 Days
• Field of Search: 707/102, 707 1- 10, 707100-1041, 707200-205, 704/275, 455/414.1, 709/220
• US Class Current: 1/1
• CPC Class Codes: G06F 16/284 Relational databases
• CPC Class Codes: G06F 16/288 Entity relationship models
• CPC Class Codes: G06F 16/86 Mapping to a database
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure

Abstract

Various techniques are provided for facilitating the management of hierarchical data within a relational database system. One such technique involves separating the storage structures used to store data that captures the information about the hierarchy (the “hierarchy structures”), from the storage structures used to store the content of the resources that belong to the hierarchy (the “content structures”). Techniques are also provided for allowing users to customize the metadata attributes associated with resources that belong to the information hierarchy. One technique involves registering XML schemas that specify the metadata attributes desired by a user. Another technique involves storing attributes that do not correspond to any declared field in a “catch-all” column within the resource table. Techniques are provided for determining how to store resources as they are added to the database. According to one technique, the database server searches the data of the resource to find content-type information. If content-type information is found, then the database server consults a content-type to content-structure mapping to determine where to store the content of the resource.

Claims

1. A computer-implemented method for managing data stored in a database system the method comprising the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources; and

wherein;

said content structures include a resource table;

said given resource is a first resource that is represented by a first row of said resource table;

location data for said first resource indicates that information in a first set of one or more tables represents content of said first resource;

said resource table includes a second row that represents a second resource;

location data for said second resource indicates that information in a second set of one or more tables represents content for said second resource; and

said first set of one or more tables are different tables than said second set of one or more tables.

2. A computer-implemented method for managing data stored in a database system, the method comprising the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources;

wherein the content structures do not store data that reflects the hierarchy of information in said information hierarchy;

creating said hierarchy structures after said content structures are created and populated; and

after creating said hierarchy structures, populating said hierarchy structures with metadata that establishes a hierarchy between information stored in said content structures without altering the structure of said content structures.

3. A computer-implemented method for managing data stored in a database system, the method comprising the steps of

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources;

wherein said plurality of resources are a first plurality of resources that belong to a first information hierarchy;

storing metadata for a second plurality of resources in said hierarchy structures, wherein said metadata includes hierarchy data that indicates a position, within a second information hierarchy, of each of the resources in said second plurality of resources; and

wherein the metadata for said first plurality of resources are stored in the same hierarchy structures as the metadata for said second plurality of resources.

4. A computer-implemented method for managing data stored in a database system the method comprising the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources; and

wherein;

said content structures include a resource table;

said given resource is a first resource that is represented by a first row of said resource table;

said resource table includes a second row that represents a second resource; and

the content of said second resource is stored in said second row, and not in any separate content structures.

5. A computer-implemented method for managing data stored in a database system, the method comprising the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources; and

wherein;

a first table that has a row corresponding to each resource in the information hierarchy, wherein each row stores metadata about the resource to which the row corresponds; and

a second table that identifies parent-child relationships of the resources that belong to said information hierarchy.

6. A computer-implemented method for managing data stored in a database system, the method comprising the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position within an information hierarchy of each of said resources; and

automatically deleting from the hierarchical structures metadata associated with the given resource in response to detecting when content associated with the given resource is deleted from said content structures.

8. The method of claim 6 further comprising storing, within the hierarchy structures, a value that specifies whether the database system should perform the step of automatically deleting from the hierarchical structures metadata associated with the given resource in response to detecting when content associated with the given resource is deleted from said content structures.

7. A computer-implemented method for managing data stored in a database system, the method comprising the step of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources; and

automatically deleting from the content structures the content of the given resource in response to detecting when metadata associated with the given resource is deleted from said hierarchy structures.

9. A computer-implemented method for managing data in a database, the method comprising the steps of:

storing, within the database, contents of resources that belong to an information hierarchy;

storing, within the database, data that captures the hierarchy of the resources that belong to said information hierarchy;

determining, based on one or more XML schemas, which metadata attributes to store for said resources;

creating one or more structures, within said database, to store said metadata attributes based on said one or more XML schemas; and

storing, within said one or more structures, values for the metadata attributes associated with said resources.

10. The method of claim 9 wherein:

the one or more structures include a table that stores values for the metadata attributes associated with a particular resource;

the one or more XML schemas include a particular XML schema that indicates metadata attributes that apply to said particular resource;

the method further comprising the steps of;

receiving input that represents a change to said particular XML schema; and

in response to said input, modifying the structure of said table.

11. The method of claim 9 wherein:

the particular XML schema is a first XML schema;

the step of receiving input includes receiving a second XML schema that identifies one or more metadata attributes that are not identified in said first XML schema; and

the step of modifying the structure includes adding to said table columns that correspond to said one or more metadata attributes that are not identified in said first XML schema.

12. The method of claim 9 wherein:

the particular XML schema is a first XML schema; and

the step of receiving input includes receiving a second XML schema that is declared as a subclass of said first XML schema.

13. The method of claim 9 wherein:

the step of determining, based on one or more XML schemas, which metadata attributes to store for said resources includes

determining based on a first XML schema a first set of metadata attributes to store for a first resource; and

determining based on a second XML schema a second set of metadata attributes to store for a second resource;

the step of storing, within said one or more structures, values for the metadata attributes associated with said resources includes

storing values for said first set of metadata attributes for said first resource; and

storing values for said second set of metadata attributes for said second resource.

14. The method of claim 13 wherein:

the step of storing values for said first set of metadata attributes includes storing in a particular table values for said first set of metadata attributes; and

the step of storing values for said second set of metadata attributes includes storing in said particular table values for said second set of metadata attributes; and

at least one attribute is not shared in common between said first set of metadata attributes and said second set of metadata attributes.

15. The method of claim 9 wherein the step of determining, based on one or more XML schemas, which metadata attributes to store for said resources includes determining, based on a particular XML schema associated with a user, which metadata attributes to store for resources associated with said user.

16. The method of claim 9 wherein the step of determining, based on one or more XML schemas, which metadata attributes to store for said resources includes determining, based on a particular XML schema associated with a particular node in the information hierarchy, which metadata attributes to store for resources that fall below said particular node in said information hierarchy.

17. The method of claim 9 wherein:

the step of determining, based on one or more XML schemas, which metadata attributes to store for said resources includes determining, based on said one or more XML schemas, that said resources may have values for metadata attributes that are not explicitly declared in said one or more XML schemas;

the step of creating one or more structures, within said database, to store said metadata attributes based on said one or more XML schemas includes creating a table that includes a catch-all column for storing data that corresponds to metadata attributes that are not explicitly declared in said one or more schemas; and

the step of storing, within said one or more structures, values for the metadata attributes associated with said resources includes storing, within said catch-all column, values for metadata attributes that are not explicitly declared in said one or more schemas.

18. The method of claim 17 wherein the step of determining that said resources may have values for metadata attributes that are not explicitly declared includes the step of determining that an XML schema of said one or more XML schemas contains an “

any”

metadata attribute.

19. The method of claim 17 further comprising the step of storing, within said catch-all column, information that specifies labels for said metadata attributes that are not explicitly declared in said one or more schemas.

20. The method of claim 9 further comprising the steps of:

receiving data associated with a resource;

identifying an XML schema that dictates the metadata attributes that apply to said resource;

detecting that said resource includes

first data associated with metadata attributes that are expressly identified in said XML schema; and

second data associated with metadata attributes that are not expressly identified in said XML schema;

storing the first data in columns that correspond to said metadata attributes that are expressly identified in said XML schema; and

storing the second data in a catch-all column.

21. The method of claim 9 further comprising the steps of:

associating first scope information with a first XML schema of said one or more XML schemas, wherein said first scope information determines the resources, within said information hierarchy, to which said first XML schema applies; and

associating second scope information with a second XML schema of said one or more XML schemas, wherein said second scope information determines the resources, within said information hierarchy, to which said second XML schema applies; and

using said first scope information and said second scope information to determine which metadata attributes apply to a particular resource.

22. A computer-implemented method for adding data, associated with a resource, to a database, the method comprising the steps of:

receiving, at a database server that manages the database, the data for the resource;

inspecting the data to locate content-type information in the data;

storing values for a set of metadata attributes for said resource in a first set of one or more tables without regard to any content-type information in the data;

selecting a second set of one or more tables based on content-type information found in said data; and

storing values for resource attributes of said resource in said second set of one or more tables.

23. The method of claim 22 wherein the step of selecting a second set of one or more tables based on content-type information found in said data includes inspecting a content-type to content-structure mapping to determine that a content-type indicated in said content-type information maps to said second set of one or more tables.

24. The method of claim 22 wherein said resource is a first resource, the method further comprising the steps of:

receiving, at said database server that manages the database, second data for a second resource;

inspecting the second data to locate second content-type information in the second data, wherein the second content-type information indicates that said second resource has a different type of content than said first resource;

storing values for metadata attributes of said second resource in said first set of one or more tables without regard to any content-type information in the second data;

selecting a third set of one or more tables based on content-type information found in said second data; and

storing values for resource attributes of said second resource in said third set of one or more tables.

25. The method of claim 22 wherein the step of inspecting the data to locate content-type information includes searching for tags, within said data, that demarcate content-type information.

26. The method of claim 22 wherein said resource is a first resource, the method further comprising the steps of:

receiving, at said database server that manages the database, second data for a second resource;

searching the second data for second content-type information in the second data;

storing values for metadata attributes of said second resource in said first set of one or more tables without regard to any content-type information in the second data;

in response to failing to find any content-type information in said second data, storing values for resource contents of said second resource in a default container.

27. The method of claim 26 wherein the default container is a LOB column within a resource table that belongs to said first set of one or more tables.

28. A tangible computer-readable medium carrying instructions for managing data stored in a database system, wherein said instructions are instructions which when executed by one or more processors, cause the one or more processors to perform the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy of each of said resources; and

wherein;

said content structures include a resource table;

said given resource is a first resource that is represented by a first row of said resource table;

location data for said first resource indicates that information in a first set of one or more tables represents content of said first resource;

said resource table includes a second row that represents a second resource;

location data for said second resource indicates that information in a second set of one or more tables represents content for said second resource; and

said first set of one or more tables are different tables than said second set of one or more tables.

29. A tangible computer-readable medium carrying instructions for managing data stored in a database system, wherein said instructions are instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy of each of said resources; and

wherein;

the content structures do not store data that reflects the hierarchy of information in said information hierarchy;

the instructions further comprising instructions for performing the steps of;

creating said hierarchy structures after said content structures are created and populated; and

after creating said hierarchy structures, populating said hierarchy structures with metadata that establishes a hierarchy between information stored in said content structures without altering the structure of said content structures.

30. A tangible computer-readable medium carrying instructions for managing data stored in a database system wherein said instructions are instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources; and

wherein;

said plurality of resources are a first plurality of resources that belong to a first information hierarchy;

the instructions further comprise instructions for performing the step of storing metadata for a second plurality of resources in said hierarchy structures, wherein said metadata includes hierarchy data that indicates a position, within a second information hierarchy, of each of the resources in said second plurality of resources; and

the metadata for said first plurality of resources are stored in the same hierarchy structures as the metadata for said second plurality of resources.

31. A tangible computer-readable medium carrying instructions for managing data stored in a database system, wherein said instructions are instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources; and

wherein;

said content structures include a resource table;

said given resource is a first resource that is represented by a first row of said resource table;

said resource table includes a second row that represents a second resource; and

the content of said second resource is stored in said second row, and not in any separate content structures.

32. A tangible computer-readable medium carrying instructions for managing data stored in a database system, wherein said instructions are instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources; and

wherein;

a first table that has a row corresponding to each resource in the information hierarchy, wherein each row stores metadata about the resource to which the row corresponds; and

a second table that identifies parent-child relationships of the resources that belong to said information hierarchy.

33. A tangible computer-readable medium carrying instructions for managing data stored in a database system, wherein said instructions are instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy of each of said resources; and

automatically deleting from the hierarchical structures metadata associated with the given resource in response to detecting when content associated with the given resource is deleted from said content structures.

35. The computer-readable medium of claim 33 further comprising instructions for performing the step of storing, within the hierarchy structures, a value that specifies whether the database system should perform the step of automatically deleting from the hierarchical structures metadata associated with the given resource in response to detecting when content associated with the given resource is deleted from said content structures.

34. A tangible computer-readable medium carrying instructions for managing data stored in a database system, wherein said instructions are instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

storing information in content structures that are separate from hierarchy structures;

storing metadata for a plurality of resources in said hierarchy structures, wherein said metadata includes;

location data, associated with a given resource of said plurality of resources, that identifies which information in said content structures represents content of said given resource; and

hierarchy data that indicates a position, within an information hierarchy, of each of said resources; and

automatically deleting from the content structures the content of the given resource in response to detecting when metadata associated with the given resource is deleted from said hierarchy structures.

36. A tangible computer-readable medium carrying instructions for managing data in a database, wherein said instructions are instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

storing, within the database, contents of resources that belong to an information hierarchy;

storing, within the database, data that captures the hierarchy of the resources that belong to said information hierarchy;

determining, based on one or more XML schemas, which metadata attributes to store for said resources;

creating one or more structures, within said database, to store said metadata attributes based on said one or more XML schemas; and

storing, within said one or more structures, values for the metadata attributes associated with said resources.

37. The computer-readable medium of claim 36 wherein:

the one or more structures include a table that stores values for the metadata attributes associated with a particular resource;

the one or more XML schemas include a particular XML schema that indicates metadata attributes that apply to said particular resource;

the instructions further comprising instructions for performing the steps of;

receiving input that represents a change to said particular XML schema; and

in response to said input, modifying the structure of said table.

38. The computer-readable medium of claim 37 wherein:

the particular XML schema is a first XML schema;

the step of receiving input includes receiving a second XML schema that identifies one or more metadata attributes that are not identified in said first XML schema; and

the step of modifying the structure includes adding to said table columns that correspond to said one or more metadata attributes that are not identified in said first XML schema.

39. The computer-readable medium of claim 37 wherein:

the particular XML schema is a first XML schema; and

the step of receiving input includes receiving a second XML schema that is declared as a subclass of said first XML schema.

40. The computer-readable medium of claim 36 wherein:

the step of determining, based on one or more XML schemas, which metadata attributes to store for said resources includes

determining based on a first XML schema a first set of metadata attributes to store for a first resource; and

determining based on a second XML schema a second set of metadata attributes to store for a second resource;

the step of storing, within said one or more structures, values for the metadata attributes associated with said resources includes

storing values for said first set of metadata attributes for said first resource; and

storing values for said second set of metadata attributes for said second resource.

41. The computer-readable medium of claim 40 wherein:

the step of storing values for said first set of metadata attributes includes storing in a particular table values for said first set of metadata attributes; and

the step of storing values for said second set of metadata attributes includes storing in said particular table values for said second set of metadata attributes; and

at least one attribute is not shared in common between said first set of metadata attributes and said second set of metadata attributes.

42. The computer-readable medium of claim 36 wherein the step of determining, based on one or more XML schemas, which metadata attributes to store for said resources includes determining, based on a particular XML schema associated with a user, which metadata attributes to store for resources associated with said user.

43. The computer-readable medium of claim 36 wherein the step of determining, based on one or more XML schemas, which metadata attributes to store for said resources includes determining, based on a particular XML schema associated with a particular node in the information hierarchy, which metadata attributes to store for resources that fall below said particular node in said information hierarchy.

44. The computer-readable medium of claim 36 wherein:

the step of determining, based on one or more XML schemas, which metadata attributes to store for said resources includes determining, based on said one or more XML schemas, that said resources may have values for metadata attributes that are not explicitly declared in said one or more XML schemas;

the step of creating one or more structures, within said database, to store said metadata attributes based on said one or more XML schemas includes creating a table that includes a catch-all column for storing data that corresponds to metadata attributes that are not explicitly declared in said one or more schemas; and

the step of storing, within said one or more structures, values for the metadata attributes associated with said resources includes storing, within said catch-all column, values for metadata attributes that are not explicitly declared in said one or more schemas.

45. The computer-readable medium of claim 44 wherein the step of determining that said resources may have values for metadata attributes that are not explicitly declared includes the step of determining that an XML schema of said one or more XML schemas contains an “

any”

metadata attribute.

46. The computer-readable medium of claim 44 further comprising instructions for performing the step of storing, within said catch-all column, information that specifies labels for said metadata attributes that are not explicitly declared in said one or more schemas.

47. The computer-readable medium of claim 36 further comprising instructions for performing the steps of:

receiving data associated with a resource;

identifying an XML schema that dictates the metadata attributes that apply to said resource;

detecting that said resource includes

first data associated with metadata attributes that are expressly identified in said XML schema; and

second data associated with metadata attributes that are not expressly identified in said XML schema;

storing the first data in columns that correspond to said metadata attributes that are expressly identified in said XML schema; and

storing the second data in a catch-all column.

48. The computer-readable medium of claim 36 further comprising instructions for performing the steps of:

associating first scope information with a first XML schema of said one or more XML schemas, wherein said first scope information determines the resources, within said information hierarchy, to which said first XML schema applies; and

associating second scope information with a second XML schema of said one or more XML schemas, wherein said second scope information determines the resources, within said information hierarchy, to which said second XML schema applies; and

using said first scope information and said second scope information to determine which metadata attributes apply to a particular resource.

49. A tangible computer-readable medium carrying instructions for adding data, associated with a resource, to a database, wherein said instructions comprising are instructions which, when executed by one or more processors cause the one or more processors to perform the steps of:

receiving, at a database server that manages the database, the data for the resource;

inspecting the data to locate content-type information in the data;

storing values for a set of metadata attributes for said resource in a first set of one or more tables without regard to any content-type information in the data;

selecting a second set of one or more tables based on content-type information found in said data; and

storing values for resource attributes of said resource in said second set of one or more tables.

50. The computer-readable medium of claim 49 wherein the step of selecting a second set of one or more tables based on content-type information found in said data includes inspecting a content-type to content-structure mapping to determine that a content-type indicated in said content-type information maps to said second set of one or more tables.

51. The computer-readable medium of claim 49 wherein said resource is a first resource, the instructions further comprising instructions for performing the steps of:

receiving, at said database server that manages the database, second data for a second resource;

inspecting the second data to locate second content-type information in the second data, wherein the second content-type information indicates that said second resource has a different type of content than said first resource;

storing values for metadata attributes of said second resource in said first set of one or more tables without regard to any content-type information in the second data;

selecting a third set of one or more tables based on content-type information found in said second data; and

storing values for resource attributes of said second resource in said third set of one or more tables.

52. The computer-readable medium of claim 49 wherein the step of inspecting the data to locate content-type information includes searching for tags, within said data, that demarcate content-type information.

53. The computer-readable medium of claim 49 wherein said resource is a first resource, the instructions further comprising instructions for performing the steps of:

receiving, at said database server that manages the database, second data for a second resource;

searching the second data for second content-type information in the second data;

storing values for metadata attributes of said second resource in said first set of one or more tables without regard to any content-type information in the second data;

in response to failing to find any content-type information in said second data, storing values for resource attributes of said second resource in a default container.

54. The computer-readable medium of claim 53 wherein the default container is a LOB column within a resource table that belongs to said first set of one or more tables.