AUTOMATED PROPAGATION OF NON-CONFLICTING QUERIES IN DISTRIBUTED DATABASES

• US 20120136898A1
• Filed: 02/02/2012
• Published: 05/31/2012
• Est. Priority Date: 10/09/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bent, Graham A., Dantressangle, Patrick, Vyvyan, David R.
• Granted Patent: US 8,560,570 B2
• Time in Patent Office: Days
• US Class Current: 707/780
• CPC Class Codes: G06F 16/2471 Distributed queries

Abstract

A logical table definition is received as part of a database query within a distributed database system. A determination is made as to whether the received logical table definition matches a local logical table definition. The query is processed in response to determining that the received logical table definition matches the local logical table definition. The query is forwarded to at least one other distributed database node.

Claims

1. A method, comprising:

receiving a logical table definition as part of a database query within a distributed database system;

determining whether the received logical table definition matches a local logical table definition;

processing the query in response to determining that the received logical table definition matches the local logical table definition; and

forwarding the query to at least one other distributed database node.

2. The method of claim 1, where determining whether the received logical table definition matches a local logical table definition comprises comparing at least one of a column name and a column data type of the received logical table definition with at least one of a column name and a column data type of the local logical table definition.

3. The method of claim 2, where determining whether the received logical table definition matches a local logical table definition comprises identifying at least one of a column name match and a column data type match between the received logical table definition and the local logical table definition.

4. The method of claim 1, where determining whether the received logical table definition matches a local logical table definition comprises identifying a match for at least one of a column name and a column data type of the received logical table definition at a position within the local logical table definition different from a position of the at least one of the column name and the column data type within the received logical table definition.

5. The method of claim 1, where processing the query in response to determining that the received logical table definition matches the local logical table definition comprises:

identifying a local physical table associated with the local logical table definition;

retrieving at least one data element from a local physical table storage location associated with the local physical table based upon a determination of at least one of a column name match and a column data type match between the received logical table definition and the local logical table definition; and

responding to the query with the retrieved at least one data element.

6. The method of claim 1, where processing the query in response to determining that the received logical table definition matches the local logical table definition comprises:

determining that a data type of at least one column of the received logical table definition is a different data type from a data type of at least one local physical table data value;

determining that the at least one local physical table data value may be cast implicitly to the data type of the at least one column of the received logical table definition; and

casting a data type of the at least one local physical table data value retrieved from a local physical table storage location associated with a local physical table mapped by the local logical table definition to the data type of the at least one column of the received logical table definition.

7. The method of claim 1, where forwarding the query to at least one other distributed database node further comprises at least one of:

forwarding the local logical table definition with the forwarded query; and

forwarding the received logical table definition with the forwarded query.

8. A system, comprising:

a memory adapted to store information associated with propagation of non-conflicting queries in distributed databases; and

a processor programmed to;

receive a logical table definition as part of a database query within a distributed database system;

store the received logical table definition to the memory;

determine whether the received logical table definition matches a local logical table definition;

process the query in response to determining that the received logical table definition matches the local logical table definition; and

forward the query to at least one other distributed database node.

9. The system of claim 8, where, in being programmed to determine whether the received logical table definition matches a local logical table definition, the processor is programmed to compare at least one of a column name and a column data type of the received logical table definition with at least one of a column name and a column data type of the local logical table definition.

10. The system of claim 9, where, in being programmed to determine whether the received logical table definition matches a local logical table definition, the processor is programmed to identify at least one of a column name match and a column data type match between the received logical table definition and the local logical table definition.

11. The system of claim 8, where, in being programmed to determine whether the received logical table definition matches a local logical table definition, the processor is programmed to identify a match for at least one of a column name and a column data type of the received logical table definition at a position within the local logical table definition different from a position of the at least one of the column name and the column data type within the received logical table definition.

12. The system of claim 8, where, in being programmed to process the query in response to determining that the received logical table definition matches the local logical table definition, the processor is programmed to:

identify a local physical table associated with the local logical table definition;

retrieve at least one data element from a local physical table storage location associated with the local physical table based upon a determination of at least one of a column name match and a column data type match between the received logical table definition and the local logical table definition; and

respond to the query with the retrieved at least one data element.

13. The system of claim 8, where, in being programmed to process the query in response to determining that the received logical table definition matches the local logical table definition, the processor is programmed to:

determine that a data type of at least one column of the received logical table definition is a different data type from a data type of at least one local physical table data value;

determine that the at least one local physical table data value may be cast implicitly to the data type of the at least one column of the received logical table definition; and

cast a data type of the at least one local physical table data value retrieved from a local physical table storage location associated with a local physical table mapped by the local logical table definition to the data type of the at least one column of the received logical table definition.

14. A computer program product comprising a computer readable storage medium including computer readable program code, where the computer readable program code when executed on a computer causes the computer to:

receive a logical table definition as part of a database query within a distributed database system;

determine whether the received logical table definition matches a local logical table definition;

process the query in response to determining that the received logical table definition matches the local logical table definition; and

forward the query to at least one other distributed database node.

15. The computer program product of claim 14, where in causing the computer to determine whether the received logical table definition matches a local logical table definition, the computer readable program code when executed on the computer causes the computer to compare at least one of a column name and a column data type of the received logical table definition with at least one of a column name and a column data type of the local logical table definition.

16. The computer program product of claim 15, where in causing the computer to determine whether the received logical table definition matches a local logical table definition, the computer readable program code when executed on the computer causes the computer to identify at least one of a column name match and a column data type match between the received logical table definition and the local logical table definition.

17. The computer program product of claim 14, where in causing the computer to determine whether the received logical table definition matches a local logical table definition, the computer readable program code when executed on the computer causes the computer to identify a match for at least one of a column name and a column data type of the received logical table definition at a position within the local logical table definition different from a position of the at least one of the column name and the column data type within the received logical table definition.

18. The computer program product of claim 14, where in causing the computer to process the query in response to determining that the received logical table definition matches the local logical table definition, the computer readable program code when executed on the computer causes the computer to:

identify a local physical table associated with the local logical table definition;

retrieve at least one data element from a local physical table storage location associated with the local physical table based upon a determination of at least one of a column name match and a column data type match between the received logical table definition and the local logical table definition; and

respond to the query with the retrieved at least one data element.

19. The computer program product of claim 14, where in causing the computer to process the query in response to determining that the received logical table definition matches the local logical table definition, the computer readable program code when executed on the computer causes the computer to:

determine that a data type of at least one column of the received logical table definition is a different data type from a data type of at least one local physical table data value;

determine that the at least one local physical table data value may be cast implicitly to the data type of the at least one column of the received logical table definition; and

cast a data type of the at least one local physical table data value retrieved from a local physical table storage location associated with a local physical table mapped by the local logical table definition to the data type of the at least one column of the received logical table definition.

20. The computer program product of claim 14, where, in causing the computer to forward the query to at least one other distributed database node, the computer readable program code when executed on the computer further causes the computer to at least one of:

forward the local logical table definition with the forwarded query; and

forward the received logical table definition with the forwarded query.