Method and system for storing and querying of markup based documents in a relational database

• US 20030182268A1
• Filed: 03/18/2002
• Published: 09/25/2003
• Est. Priority Date: 03/18/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lal, Amrish K.
• Granted Patent: US 6,832,219 B2
• Time in Patent Office: Days
• US Class Current: 707/3
• CPC Class Codes: G06F 16/86 Mapping to a database
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching

Abstract

An apparatus, article of manufacture and computer-based markup serialization method is provided for transferring data contained in a markup based document, such as an Extensible Markup Language (XML) document, into a relational database stored in an electronic storage device having a database management system. They are used for easy subsequent retrieval of data from the database in the XML format and reconstruction of the XML document. The method decomposes the document according to basic markup types of the documents'"'"' data components and stores the decomposed document in a set of markup tables created in the database, one markup table for each basic markup type, thereby preserving the hierarchical tree structure, parent-child order, and components of the document. For querying the database markup tables the method uses SQL queries to retrieve the XML document components in the XML format.

Claims

1. A computer-based markup serialization method for transferring data contained in an Extensible Markup Language (XML) document into a relational database stored in an electronic storage device having a database management system, for easy subsequent retrieval of data from the database in the XML format and reconstruction of the XML document, the method comprising the steps of:

(a) decomposing the XML document according to basic markup types of XML documents'"'"' data components; and

(b) storing the decomposed XML document in a set of markup tables created in the database, one markup table for each basic markup type.

2. The method according to claim 1, wherein the basic markup types are selected from a group comprising ATTRIBUTE, CDATA₁₃ SECTION, COMMENT, DOCUMENT₁₃ FRAGMENT, DOCUMENT, DOCUMENT₁₃ TYPE, ELEMENT, ENTITY, ENTITY₁₃ REFERENCE, NOTATION, PROCESSING₁₃ INSTRUCTION and TEXT markup types.

3. The method according to claim 1, wherein the decomposing step includes parsing the XML document to create a nested XML parse tree, and serializing the XML parse tree by traversing the path of each node from the root, wherein a basic markup type of each said node is identified by a markup tag in the XML document describing the markup type of a data component following the markup tag, and wherein each said node is described by a name, attributes, and an id representing the position of said node in the XML parse tree.

4. The method according to claim 3, wherein in the storing step each said node data is stored in a record of at least one markup table according to the node'"'"'s markup type, and wherein each said record contains a node id, node name (NAME), node parent (PID), and node data value (VALUE) columns.

5. The method according to claim 4, wherein the XML parse tree root, node elements, node element'"'"'s descendants and siblings are stored in an ELEMENT table, and each node element'"'"'s attribute is stored in an ATTRIBUTE table, and wherein the node parent PID of each said ATTRIBUTE table record points to the id of the node element record in the ELEMENT table.

6. The method according to claim 1, further comprising a step of querying the database markup tables using SQL queries to retrieve the XML document components in the XML format.

7. The method according to claim 6, wherein the querying step creating an XML result set in two stages, a SQL querying stage querying the markup tables to obtain a data result set, and a result set transformation stage for re-formatting the data result set to an XML data result set.

8. The method according to claim 7, further comprising a step of creating a reconstructed XML document by selecting all elements from the markup tables in the querying step.

9. A computer-based XML markup serialization processor system for transferring data contained in an Extensible Markup Language (XML) document into a relational database stored in an electronic storage device having a database management system, for easy subsequent retrieval of data from the database in the XML format and reconstruction of the XML document, the system comprising:

means for decomposing the XML document according to basic markup types of XML documents'"'"' data components; and

means for storing the decomposed XML document in a set of markup tables created in the database, one markup table for each basic markup type.

10. The system according to claim 9, wherein the basic markup types are selected from a group comprising ATTRIBUTE, CDATA₁₃ SECTION, COMMENT, DOCUMENT₁₃ FRAGMENT, DOCUMENT, DOCUMENT₁₃ TYPE, ELEMENT, ENTITY, ENTITY₁₃ REFERENCE, NOTATION, PROCESSING₁₃ INSTRUCTION and TEXT markup types.

11. The system according to claim 9, wherein the decomposing means includes means for parsing the XML document to create a nested XML parse tree, and serializing the XML parse tree by traversing the path of each node from the root, wherein a basic markup type of each said node is identified by a markup tag in the XML document describing the markup type of a data component following the markup tag, and wherein each said node is described by a name, attributes, and an id representing the position of said node in the XML parse tree.

12. The system according to claim 11, wherein with the storing means each said node data is stored in a record of at least one markup table according to the node'"'"'s markup type, and wherein each said record contains a node id, node name (NAME), node parent (PID), and node data value (VALUE) columns.

13. The system according to claim 12, wherein the XML parse tree root, node elements, node element'"'"'s descendants and siblings are stored in an ELEMENT table, and each node element'"'"'s attribute is stored in an ATTRIBUTE table, and wherein the node parent PID of each said ATTRIBUTE table record points to the id of the node element record in the ELEMENT table.

14. The system according to claim 9, further comprising a means for querying the database markup tables using SQL queries to retrieve the XML document components in the XML format.

15. The system according to claim 14, wherein the querying means creating an XML result set in two stages, a SQL querying stage querying the markup tables to obtain a data result set, and a result set transformation stage for re-formatting the data result set to an XML data result set.

16. The system according to claim 15, further comprising a means for creating a reconstructed XML document by selecting all elements from the markup tables in the query.

17. A computer usable medium tangibly embodying a program of instructions executable by the computer to perform a computer-based markup serialization method for transferring data contained in an Extensible Markup Language (XML) document into a relational database stored in an electronic storage device having a database management system, for easy subsequent retrieval of data from the database in the XML format and reconstruction of the XML document, the method comprising the steps of:

(a) decomposing the XML document according to basic markup types of XML documents'"'"' data components; and

(b) storing the decomposed XML document in a set of markup tables created in the database, one markup table for each basic markup type.

18. The method according to claim 17, wherein the basic markup types are selected from a group comprising ATTRIBUTE, CDATA₁₃ SECTION, COMMENT, DOCUMENT₁₃ FRAGMENT, DOCUMENT, DOCUMENT₁₃ TYPE, ELEMENT, ENTITY, ENTITY₁₃ REFERENCE, NOTATION, PROCESSING₁₃ INSTRUCTION and TEXT markup types.

19. The method according to claim 17, wherein the decomposing step includes parsing the XML document to create a nested XML parse tree, and serializing the XML parse tree by traversing the path of each node from the root, wherein a basic markup type of each said node is identified by a markup tag in the XML document describing the markup type of a data component following the markup tag, and wherein each said node is described by a name, attributes, and an id representing the position of said node in the XML parse tree.

20. The method according to claim 19, wherein in the storing step each said node data is stored in a record of at least one markup table according to the node'"'"'s markup type, and wherein each said record contains a node id, node name (NAME), node parent (PID), and node data value (VALUE) columns.

21. The method according to claim 20, wherein the XML parse tree root, node elements, node element'"'"'s descendants and siblings are stored in an ELEMENT table, and each node element'"'"'s attribute is stored in an ATTRIBUTE table, and wherein the node parent PID of each said ATTRIBUTE table record points to the id of the node element record in the ELEMENT table.

22. The method according to claim 17, further comprising a step of querying the database markup tables using SQL queries to retrieve the XML document components in the XML format.

23. The method according to claim 22, wherein the querying step creating an XML result set in two stages, a SQL querying stage querying the markup tables to obtain a data result set, and a result set transformation stage for reformatting the data result set to an XML data result set.

24. The method according to claim 23, further comprising a step of creating a reconstructed XML document by selecting all elements from the markup tables in the querying step.

25. A computer-based markup serialization method for transferring data contained in a markup based document into a relational database stored in an electronic storage device having a database management system, for easy subsequent retrieval of data from the database in the original document format and reconstruction of the document, the method comprising the steps of:

(a) decomposing the markup based document according to basic markup types of the documents'"'"' data components; and

(b) storing the decomposed document in a set of markup tables created in the database, one markup table for each basic markup type.

26. The method according to claim 25, wherein the decomposing step includes parsing the document to create a nested parse tree, and serializing the parse tree by traversing the path of each node from the root, wherein a basic markup type of each said node is identified by a markup tag in the document describing the markup type of a data component following the markup tag, and wherein each said node is described by a name, attributes, and an id representing the position of said node in the parse tree.

27. The method according to claim 26, wherein in the storing step each said node data is stored in a record of at least one markup table according to the node'"'"'s markup type, and wherein each said record contains a node id, node name (NAME), node parent (PID), and node data value (VALUE) columns.

28. The method according to claim 27, wherein the parse tree root, node elements, node element'"'"'s descendants and siblings are stored in an ELEMENT table, and each node element'"'"'s attribute is stored in an ATTRIBUTE table, and wherein the node parent PID of each said ATTRIBUTE table record points to the id of the node element record in the ELEMENT table.

29. The method according to claim 25, further comprising a step of querying the database markup tables using SQL queries to retrieve the document components in the original document format.

30. The method according to claim 29, further comprising a step of creating a reconstructed document by selecting all elements from the markup tables in the querying step.

31. A computer-based markup serialization processor system for transferring data contained in a markup based document into a relational database stored in an electronic storage device having a database management system, for easy subsequent retrieval of data from the database in the original document format and reconstruction of the document, the system comprising:

means for decomposing the markup based document according to basic markup types of the documents'"'"' data components; and

means for storing the decomposed document in a set of markup tables created in the database, one markup table for each basic markup type.

32. The system according to claim 31, wherein the decomposing means includes means for parsing the document to create a nested parse tree, and serializing the parse tree by traversing the path of each node from the root, wherein a basic markup type of each said node is identified by a markup tag in the document describing the markup type of a data component following the markup tag, and wherein each said node is described by a name, attributes, and an id representing the position of said node in the parse tree.

33. The system according to claim 32, wherein with the storing means each said node data is stored in a record of at least one markup table according to the node'"'"'s markup type, and wherein each said record contains a node id, node name (NAME), node parent (PID), and node data value (VALUE) columns.

34. The system according to claim 33, wherein the parse tree root, node elements, node element'"'"'s descendants and siblings are stored in an ELEMENT table, and each node element'"'"'s attribute is stored in an ATTRIBUTE table, and wherein the node parent PID of each said ATTRIBUTE table record points to the id of the node element record in the ELEMENT table.

35. The system according to claim 31, further comprising a means for querying the database markup tables using SQL queries to retrieve the document components in the original document format.

36. The system according to claim 35, further comprising a means for creating a reconstructed document by selecting all elements from the markup tables in the query.

37. A computer usable medium tangibly embodying a program of instructions executable by the computer to perform a computer-based markup serialization method for transferring data contained in a markup based document into a relational database stored in an electronic storage device having a database management system, for easy subsequent retrieval of data from the database in the original document format and reconstruction of the document, the method comprising the steps of:

(a) decomposing the markup based document according to basic markup types of the documents'"'"' data components; and

(b) storing the decomposed document in a set of markup tables created in the database, one markup table for each basic markup type.

38. The method according to claim 37, wherein the decomposing step includes parsing the document to create a nested parse tree, and serializing the parse tree by traversing the path of each node from the root, wherein a basic markup type of each said node is identified by a markup tag in the document describing the markup type of a data component following the markup tag, and wherein each said node is described by a name, attributes, and an id representing the position of said node in the parse tree.

39. The method according to claim 38, wherein in the storing step each said node data is stored in a record of at least one markup table according to the node'"'"'s markup type, and wherein each said record contains a node id, node name (NAME), node parent (PID), and node data value (VALUE) columns.

40. The method according to claim 39, wherein the parse tree root, node elements, node element'"'"'s descendants and siblings are stored in an ELEMENT table, and each node element'"'"'s attribute is stored in an ATTRIBUTE table, and wherein the node parent PID of each said ATTRIBUTE table record points to the id of the node element record in the ELEMENT table.

41. The method according to claim 37, further comprising a step of querying the database markup tables using SQL queries to retrieve the document components in the original document format.

42. The method according to claim 41, further comprising a step of creating a reconstructed document by selecting all elements from the markup tables in the querying step.