Flexible storage of XML collections within an object-relational database

• US 20070083542A1
• Filed: 10/07/2005
• Published: 04/12/2007
• Est. Priority Date: 10/07/2005
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Sedlar, Eric, Agrawal, Abhyudaya, Chandrasekar, Sivasankaran, Murthy, Ravi, Agarwal, Nipun
• Granted Patent: US 9,367,642 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/83 Querying
• CPC Class Codes: G06F 7/00 Methods or arrangements for processing data by operating upon the order or content of the data handled logic circuits H03K19/00

Abstract

A database server determines, on an element-level of granularity, what form of VARRAY storage to map collections of elements defined by a XML schema. A collection element may be mapped to an in-line VARRAY or an out-of-line VARRAY. The determination may based on a variety of factors, including the database type mapped to the collection element, database limitations that limit the form storage for certain database types, and annotations (“mapping annotations”) embedded within that XML schema that specifying a database type for database representation of a collection element or a form of VARRAY storage.

Claims

1. A method used for managing XML data in a database system, comprising the steps of:

a database server receiving a XML schema;

wherein said XML schema includes a plurality of declarations, each declaration of said plurality of declarations defining a collection element; and

for each declaration of said plurality of declarations;

making, based one or more factors, a certain determination of a form of VARRAY storage to use for a database representation of the respective collection element, and

said database server generating mapping data that maps said respective collection element to the form of VARRAY storage determined by said certain determination.

2. The method of claim 1, wherein the form of VARRAY storage determined by said certain determination is inline storage.

3. The method of claim 1, wherein the form of VARRAY storage determined by said certain determination is out-of-line storage.

4. The method of claim 1, wherein the one or more factors include a database type of the database representation.

5. The method of claim 4, wherein the one or more factors are based on a limitation on forms of VARRAY storage supported by said database server for the database type.

6. The method of claim 1, wherein:

a particular declaration of said plurality of declarations includes a mapping annotation mapping said respective collection element to a form of VARRAY storage; and

wherein the one or more factors is based on said mapping annotation.

7. The method of claim 6, wherein:

said XML schema specifies a default form of VARRAY storage; and

said one or more factors are based on said form of VARRAY storage.

11. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 1.

12. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 2.

13. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 3.

14. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 4.

15. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 5.

16. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 6.

17. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 7.

8. A computer-implemented method for mapping a database representation in a database to XML elements defined by a XML schema, comprising the steps of:

a database server evaluating said XML schema, wherein said XML schema includes a plurality of declarations, each declaration of said plurality of declarations defining a collection element; and

wherein said evaluation includes, for each declaration of said plurality of declarations;

making a determination specific to said each declaration of whether to use an inline VARRAY or an out-of-line VARRAY as a database representation of the respective collection element, and

said database server generating mapping data that;

maps said respective collection element to a VARRAY column of a table in said database, and

indicates whether the VARRAY column is stored inline or out-of-line.

9. The method of claim 8, wherein making a determination specific to said each declaration of whether to use an inline VARRAY or an out-of-line VARRAY is based on a database type of said database representation.

10. The method of claim 8, wherein:

a particular declaration of said plurality of declarations includes a mapping annotation mapping said respective collection element to a form of VARRAY storage; and

making a determination specific to said each declaration of whether to use an inline VARRAY or an out-of-line VARRAY is based on said mapping annotation.

18. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 8.

19. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 9.

20. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 10.