Interleaving Query Transformations For XML Indexes

• US 20100036825A1
• Filed: 08/08/2008
• Published: 02/11/2010
• Est. Priority Date: 08/08/2008
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Tarachandani, Asha, Baby, Thomas, Chandrasekar, Sivasankaran, Agarwal, Nipun
• Granted Patent: US 7,958,112 B2
• Time in Patent Office: Days
• US Class Current: N/A
• CPC Class Codes: G06F 16/8365 Query optimisation

Abstract

During query optimization, XML index and view merge transformations may be interleaved.

Claims

1. A method of transforming a query, comprising:

applying a view merge to said query; and

after applying a view merge to said query, applying a XML index rewrite to said query.

2. The method of claim 1, further including:

after applying a XML index rewrite to said query, applying another view merge to said query.

3. The method of claim 1, wherein:

applying an XML index includes creating an inline view; and

wherein applying another view merge includes merging said inline view.

4. The method of claim 2,

wherein an XML repository contains XML documents;

wherein said XML repository contains a table;

wherein rows of said table each contain a single node value of node values in said XML documents; and

wherein said inline view references said table.

5. The method of claim 1, further including after applying a view merge to said query and before applying an XML rewrite to said query, applying at least one other query transformation to said query.

6. A method of transforming a query, comprising:

applying an XML index rewrite to said query;

after applying said XML index rewrite to said query, applying a view merge to said query; and

after applying a view merge to said query, applying another XML index rewrite to said query.

7. The method of claim 6, wherein:

applying an XML index includes creating an inline view; and

wherein applying a view merge includes merging said inline view.

8. The method of claim 7,

wherein an XML repository contains XML documents;

wherein said XML repository contains a table;

wherein rows of said table each contain a single node value of node values in said XML documents; and

wherein said inline view references said table.

9. The method of claim 6, after applying an XML rewrite to said query and before applying a view merge to said query, applying at least one other query transformation to said query.