Querying and fragment extraction within resources in a hierarchical repository

• US 7,840,590 B2
• Filed: 12/18/2006
• Issued: 11/23/2010
• Est. Priority Date: 12/18/2006
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Tam, Man-Hay, Baby, Thomas, Agarwal, Nipun
• Primary Examiner(s): Vo; Tim T.
• Assistant Examiner(s): Fan; Shiow-Jy
• Application Number:
  US11/641,379
• Publication Number:
  US 20080147614A1
• Time in Patent Office: 1,436 Days
• Field of Search: 707/1, 707/3, 707/10, 707/E17.014, 707/E17.132, 707/999.003, 707/696, 707/716, 707/741, 707/769
• US Class Current: 707/769
• CPC Class Codes: G06F 16/8373 Query execution

Abstract

Techniques for efficiently processing a query are provided. A query may specify a location path and a content path. The location path identifies the hierarchical location of a set of documents within a resource repository. The content path identifies hierarchical location of one or more nodes within the content of the set of documents. Computing the query includes using a repository index, based on the location path and the content path, to generate first results corresponding to the set of documents and second results corresponding to the one or more nodes. Final results of the query are based on the first results and second results. Another technique is provided for formatting a locator value in the repository index to support data that is stored object-relationally. Another technique is provided for storing index information about virtual content.

Claims

1. A machine-implemented method, comprising the steps of:

receiving a query that requests data from a resource repository that stores multiple resources in a resource hierarchy;

wherein content of each of the multiple resources conforms to a hierarchical markup language;

wherein the query includes;

a resource location path that (a) identifies a hierarchical location of a first set of one or more resources within the resource hierarchy of the resource repository (b) without identifying any particular content of a resource in the resource repository, and

a content path that identifies a hierarchical location of one or more nodes within content of a second set of one or more resources;

storing an index that includes;

entries that index resource location paths for a plurality of resources within the resource hierarchy, and

entries that index content paths for the plurality of resources;

computing the query, wherein computing includes;

using, based on the resource location path, said index to generate first results that identify the first set of one or more resources, and

using, based on the content path, said index to generate second results that identify the one or more nodes and that identify the second set of one or more resources; and

computing results of the query based on the first results and the second results, wherein the results of the query identify a particular set of one or more resources that are a subset of (1) the first set of one or more resources and (2) the second set of one or more resources;

wherein the steps are performed on one or more computing devices.

2. The method of claim 1, wherein the content of a resource of the multiple resources includes at least one of the following:

system properties of the resource, user-defined properties of the resource, and the data of the resource.

3. The method of claim 2, wherein:

the content includes system properties of the resource; and

the system properties of each resource in the resource repository conform to a particular XML schema.

4. The method of claim 2, wherein:

the content includes user-defined properties of the resource; and

a subset of the user-defined properties do not conform to a particular XML schema.

5. The method of claim 2, wherein:

the content includes the data of the resource; and

a subset of the data does not conform to a particular XML schema.

6. The method of claim 1, wherein:

the index comprises a path identifier column and a locator column; and

a bit in the locator column of an index entry indicates whether the corresponding path identifier indicates a resource location path of the resource that corresponds to said index entry or an XPath string of a node, in the resource, that corresponds to said index entry.

7. The method of claim 1, wherein:

said content path includes an XPath string that identifies said one or more nodes within said second set of one or more resources in said resource repository; and

said index is used to lookup said resource location path and said XPath string.

8. The method of claim 1, wherein a subset of said plurality of resources is stored outside of said resource repository when said index is generated.

9. The method of claim 1, wherein:

each resource of the multiple resources is associated with one or more properties; and

at least one of said one or more properties is stored on disk as one datatype and resides in memory as a different datatype.

10. The method of claim 1, wherein:

a first subset of said plurality of resources are stored in an object-relational (O-R) format,

a second subset of said plurality of resources are stored in a large object (LOB) format, and

the index includes a locator column that is used as both a locator of resources stored in the O-R format and a locator of resources stored in the LOB format.

11. The method of claim 10, wherein the LOB format includes at least one of the following formats:

text within a character large object (CLOB) and encoded binary XML in a binary large object (BLOB).

12. The method of claim 10, wherein:

the query specifies an XPath string that indicates a fragment is to be extracted;

the fragment is a portion of a particular resource of said plurality of resources;

the particular resource is an XML document conforming to an XML schema;

the index is used to determine a locator value, corresponding to the locator column, of one or more nodes specified by the XPath string; and

the locator value is used to extract the fragment from where the particular resource is stored.

13. The method of claim 1, wherein the resource location path includes at least one directory name.

14. One or more storage media storing instructions which, when executed by one or more processors, cause:

receiving a query that requests data from a resource repository that stores multiple resources in a resource hierarchy;

wherein content of each of the multiple resources conforms to a hierarchical markup language;

wherein the query includes;

a resource location path that identifies (a) a hierarchical location of a first set of one or more resources within the resource hierarchy of the resource repository (b) without identifying any particular content of a resource in the resource repository, and

a content path that identifies a hierarchical location of one or more nodes within content of a second set of one or more resources;

storing an index that includes;

entries that index resource location paths for a plurality of resources within the resource hierarchy, and

entries that index content paths for the plurality of resources;

computing the query, wherein computing includes;

using, based on the resource location path, said index to generate first results that identify the first set of one or more resources, and

using, based on the content path, said index to generate second results that identify the one or more nodes and that identify the second set of one or more resources; and

computing results of the query based on the first results and the second results, wherein the results of the query identify a particular set of one or more resources that are a subset of (1) the first set of one or more resources and (2) the second set of one or more resources.

15. The one or more storage media of claim 14, wherein the content of a resource of the multiple resources includes at least one of the following:

system properties of the resource, user-defined properties of the resource, and the data of the resource.

16. The one or more storage media of claim 15, wherein:

the content includes system properties of the resource; and

the system properties of each resource in the resource repository conform to a particular XML schema.

17. The one or more storage media of claim 15, wherein:

the content includes user-defined properties of the resource; and

a subset of the user-defined properties do not conform to a particular XML schema.

18. The one or more storage media of claim 15, wherein:

the content includes the data of the resource; and

a subset of the data does not conform to a particular XML schema.

19. The one or more storage media of claim 14, wherein:

the index comprises a path identifier column and a locator column; and

a bit in the locator column of an index entry indicates whether the corresponding path identifier indicates a resource location path of the resource that corresponds to said index entry or an XPath string of a node, in the resource, that corresponds to said index entry.

20. The one or more storage media of claim 14, wherein:

said content path includes an XPath string that identifies said one or more nodes within said second set of one o more resources in said resource repository; and

said index is used to lookup said resource location path and said XPath string.

21. The one or more storage media of claim 14, wherein a subset of said plurality of resources is stored outside of said resource repository when said index is generated.

22. The one or more storage media of claim 14, wherein:

each resource of the multiple resources is associated with one or more properties; and

at least one of said one or more properties is stored on disk as one datatype and resides in memory as a different datatype.

23. The one or more storage media of claim 14, wherein:

a first subset of said plurality of resources are stored in an object-relational (O-R) format,

a second subset of said plurality of resources are stored in a large object (LOB) format, and

the index includes a locator column that is used as both a locator of resources stored in the O-R format and a locator of resources stored in the LOB format.

24. The one or more storage media of claim 23, wherein the LOB format includes at least one of the following formats:

text within a character large object (CLOB) and encoded binary XML in a binary large object (BLOB).

25. The one or more storage media of claim 23, wherein:

the query specifies an XPath string that indicates a fragment is to be extracted;

the fragment is a portion of a particular resource of said plurality of resources;

the particular resource is an XML document conforming to an XML schema;

the index is used to determine a locator value, corresponding to the locator column, of one or more nodes specified by the XPath string; and

the locator value is used to extract the fragment from where the particular resource is stored.

26. The one or more storage media of claim 14, wherein the resource location path includes at least one directory name.