INDEX STRUCTURE FOR A RELATIONAL DATABASE TABLE

• US 20150026189A1
• Filed: 06/27/2014
• Published: 01/22/2015
• Est. Priority Date: 07/19/2013
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Li, Lei, Li, Peng, Wang, Xi Ning, Wu, Ya Xin, Zhou, Ying Hua
• Granted Patent: US 9,600,507 B2
• Time in Patent Office: Days
• US Class Current: 707/741
• CPC Class Codes: G06F 16/2228 Indexing structures
• CPC Class Codes: G06F 16/245 Query processing
• CPC Class Codes: G06F 16/284 Relational databases
• CPC Class Codes: G06F 16/81 Indexing, e.g. XML tags; Data structures therefor; Storage structures
• CPC Class Codes: G06F 16/93 Document management systems

Abstract

Embodiments are directed to building an index structure for a relational database (RDB) table and for querying the RDB table. An aspect includes obtaining JSON documents from a RDB table, identifying JSON objects in the JSON documents and assigning identifiers for them, and building an index structure according to values in the JSON objects such that the index structure includes at least one node that records values in a JSON object and includes the identifier of the specific JSON object. Querying the RDB table includes receiving a query request including an indicator which indicates that the query is to be performed on JSON objects, and searching the index structure based on query conditions in the query request so as to determine a target JSON object that meets the query conditions.

Claims

1. A method for building an index structure for a relational database table, comprising:

obtaining at least one JavaScript Object Notation (JSON) document from the relational database table;

identifying a plurality of JSON objects in the at least one JSON document and assigning identifiers for the plurality of JSON objects; and

building the index structure according to values in the plurality of JSON objects such that the index structure includes at least one node which records the values in one of the plurality of JSON objects and includes a corresponding identifier of the one of the plurality of JSON objects.

2. The method of claim 1, wherein identifying the plurality of JSON objects in the at least one JSON document comprises identifying the plurality of JSON objects by identifying indicative symbols in the at least one JSON document.

3. The method of claim 1, wherein assigning identifiers for the plurality of JSON objects comprises assigning global identifiers for the identified JSON objects.

4. The method of claim 1, wherein assigning the identifiers for the plurality of JSON objects comprises determining document IDs for JSON documents corresponding to the identified JSON objects, assigning object IDs within corresponding JSON documents for the identified JSON objects, and combining the document IDs and the object IDs as the identifiers.

5. The method of claim 4, wherein assigning the object IDs within the JSON documents for the identified JSON objects comprises generating the object IDs for the identified JSON objects.

6. The method of claim 4, wherein assigning the object IDs within the JSON documents for the identified JSON objects comprises using JSON paths corresponding to the identified JSON objects as the object IDs.

7. The method of claim 1, wherein the at least one node is a leaf node of the index structure.

8. A method for querying a relational database table, comprising:

receiving a query request including an indicator which indicates that a query subject to the query request is to be performed on JSON objects in at least one JSON document included in the relational database table; and

searching an index structure based on query conditions in the query request, and determining a target JSON object that meets the query conditions.

9. The method of claim 8, wherein determining the target JSON object meets the query conditions comprises:

determining a target node that records the target JSON object in the index structure based on values specified in the query conditions; and

locating the target JSON object in the relational database table using an identifier recorded in the target node.

10. An apparatus for building an index structure for a relational database table, comprising:

a document obtaining unit configured to obtain at least one JSON document from the relational database table;

an identifying unit configured to identify a plurality of JSON objects in the at least one JSON document and assign identifiers for the plurality of JSON objects; and

an index building unit configured to build the index structure according to values in the plurality of JSON objects such that the index structure includes at least one node which records the values in one of the plurality of JSON objects and includes a corresponding identifier of the one of the plurality of JSON objects.

11. The apparatus of claim 10, wherein the document identifying unit is configured to identify the plurality of JSON objects by identifying indicative symbols in the at least one JSON document.

12. The apparatus of claim 10, wherein the identifying unit is configured to assign global identifiers for the identified JSON objects.

13. The apparatus of claim 10, wherein the identifying unit is configured to determine document IDs for JSON documents corresponding to the identified JSON objects, assign object IDs within corresponding JSON documents for the identified JSON objects, and combine the document IDs and the object IDs as the identifiers.

14. The apparatus of claim 13, wherein the identifying unit is further configured to generate the object IDs for the identified JS ON objects.

15. The apparatus of claim 13, wherein the identifying unit is further configured to use JSON paths corresponding to the identified JSON objects as the object IDs.

16. The apparatus of claim 10, wherein the at least one node is a leaf node of the index structure.

17. An apparatus for querying a relational database table, comprising:

a receiving unit configured to receive a query request including an indicator which indicates that a query subject to the query request is to be performed on JSON objects in at least one JSON document included in the relational database table; and

a querying unit configured to search an index structure based on query conditions in the query request, and determine a target JSON object that meets the query conditions.

18. The apparatus of claim 17, wherein the querying unit is configured to:

determine a target node that records the target JSON object in the index structure based on values specified in the query conditions; and

locate the target JSON object in the relational database table using an identifier recorded in the target node.