Method and system for handling binary large objects

• US 20120011178A1
• Filed: 07/09/2010
• Published: 01/12/2012
• Est. Priority Date: 07/09/2010
• Status: Active Grant

• Current Assignee: HERE Global B.V. (HERE Holding Corporation)
• Original Assignee: Navteq North America LLC (HERE Holding Corporation)
• Inventors: Pfeifle, Martin, Richter, Jan
• Granted Patent: US 8,756,261 B2
• Time in Patent Office: Days
• US Class Current: 707/825
• CPC Class Codes: G06F 16/2219 Large Object storage; Management thereof

Abstract

A method and system for efficiently storing, retrieving, and updating binary large objects (BLOBs) in embedded systems is disclosed. The metadata of the BLOBs is stored in relational tables, while the BLOBs are stored in a flat file. Querying the metadata of the BLOBs (i.e. the starting points of the BLOBs and their length) is performed based on SQL. The corresponding BLOBs are then accessed using file operation commands. To further simplify the querying and storage of BLOBs, virtual tables are created. By using these virtual tables, a user can access a BLOB as if it was stored in a physical table.

Claims

1. A computer-implemented method of storing a binary large object in an embedded system, comprising:

receiving a binary large object and an identifier associated with the binary large object by a database system;

storing the binary large object in a flat file external from the database system starting at a position in memory and extending to a length of the binary large object; and

storing the identifier, the length, and the position in a relational table within the database system.

2. The method of claim 1, further comprising creating a virtual table, wherein the virtual table allows a user of the database system to identify the binary large object.

3. The method of claim 2, wherein the virtual table allows the user of the database system to retrieve the binary large object.

4. The method of claim 2, wherein the virtual table allows the user of the database system to update the binary large object.

5. The method of claim 1, wherein the binary large object includes geographic data.

6. The method of claim 1, further comprising retrieving the binary large object by querying the relational table and using file operations to read the binary large object from the flat file.

7. The method of claim 1, further comprising updating the binary large object.

8. The method of claim 7, further comprising moving the binary large object to a second position in the flat file and updating the length and the position in the relational table if updating the binary large object increases the length of the binary large object.

9. The method of claim 8, further comprising creating a second relational table within the database system and storing the length and the position of the binary large object prior to the update and the move in the second relational table.

10. The method of claim 9, further comprising storing a second binary large object starting at the position identified in the second relational table.

11. The method of claim 1, further comprising compressing the binary large object prior to storing the binary large object in the flat file.

12. The method of claim 11, further comprising decompressing the binary large object after retrieving the compressed binary large object from the flat file.

13. The method of claim 1, adding a gap in the flat file after storing the binary large object and prior to storing a second binary large object.

14. A computer-implemented method of handling a binary large object in an embedded system, comprising:

creating a virtual table that allows a user to identify a binary large object and an associated identifier to a database system, wherein the virtual table is associated with a module that contains instructions to perform actions on the virtual table;

receiving an instruction to insert the binary large object and the identifier associated with the binary large object in the virtual table;

the module storing the binary large object in a flat file external from the database system starting at a position in memory and extending to the length of the binary large object; and

the module storing the identifier, the length, and the position in a relational table within the database system.

15. A system for storing a binary large object in an embedded system, comprising in combination:

a database system including a virtual table and a module that includes at least one physical table; and

a flat file external to the database system that includes binary large objects that can be retrieved and updated by querying the virtual table and using metadata stored in the at least one physical table.

16. The system of claim 15, wherein the virtual table includes a binary large object and an identifier associated with the binary large object.

17. The system of claim 15, wherein the metadata identifies start and length of the binary large object stored in the flat file.

18. The system of claim 15, wherein the metadata identifies free spaces in the flat file.

19. The system of claim 15, wherein the metadata identifies attributes of the binary large objects.

20. The system of claim 15, wherein the binary large objects include geographic data.