Automated propagation of non-conflicting queries in distributed databases

• US 8,145,652 B2
• Filed: 10/09/2008
• Issued: 03/27/2012
• Est. Priority Date: 10/09/2008
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bent, Graham A., Dantressangle, Patrick, Vyvyan, David R.
• Primary Examiner(s): Stevens, Robert
• Assistant Examiner(s): Ly, Anh
• Application Number:
  US12/248,082
• Publication Number:
  US 20100094892A1
• Time in Patent Office: 1,265 Days
• Field of Search: 707/755, 707/756, 707/758, 707/760, 707/770, 707/781, 709/203
• US Class Current: 707/755
• CPC Class Codes: G06F 16/2471 Distributed queries

Abstract

A logical table definition is received in association with 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. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.

Claims

1. A method, comprising:

receiving, via a processor, a logical table definition in association with a database query within a distributed database system;

determining whether the received logical table definition matches a local logical table definition, where determining whether the received logical table definition matches the 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; and

identifying a match for the at least one of the column name and the 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;

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 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 comprises determining whether there is the at least one of the column name match and the column data type match between the received logical table definition and the local logical table definition.

3. 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 the column name match and the 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.

4. The method of claim 1, where forwarding the query to at least one other distributed database node comprises forwarding the received logical table definition with the forwarded query.

5. The method of claim 1, further comprising generating a warning when the local logical table definition does not match the received logical table definition and sending the warning in response to the database query.

6. A method, comprising:

receiving, via a processor, a logical table definition in association with 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, where processing the query in response to determining that the received logical table definition matches the local logical table definition comprises;

determining whether 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; and

determining whether 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 in response to determining that the data type of the at least one column of the received logical table definition is different from the data type of the at least one local physical table data value; and

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

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

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 in response to determining that the data type of the at least one column of the received logical table definition is different from the data type of the at least one local physical table data value and that the at least one physical table data value may be cast implicitly to the data type of the at least one column of the received logical table definition.

8. The method of claim 7, where forwarding the query to at least one other distributed database node comprises forwarding the local logical table definition with the forwarded query.

9. 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 in association with 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, where, in being programmed to determine whether the received logical table definition matches the 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; and

identify a match for the at least one of the column name and the 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;

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.

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

11. The system of claim 9, 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 the at least one of the column name match and the 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.

12. The system of claim 9, where, in being programmed to forward the query to at least one other distributed database node, the processor is programmed to generate a warning when the local logical table definition does not match the received logical table definition and send the warning in response to the database query.

13. The system of claim 9, where the processor is further programmed to generate a warning when the local logical table definition does not match the received logical table definition and send the warning in response to the database query.

14. 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 in association with 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, 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 whether 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; and

determine whether 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 in response to determining that the data type of the at least one column of the received logical table definition is different from the data type of the at least one local physical table data value, and

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

15. The system of claim 14, 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 further programmed to:

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 in response to determining that the data type of the at least one column of the received logical table definition is different from the data type of the at least one local physical table data value and that the at least one physical table data value may be cast implicitly to the data type of the at least one column of the received logical table definition.

16. The system of claim 15, where, in being programmed to forward the query to at least one other distributed database node, the processor is programmed to forward at least one of the local logical table definition and the received logical table definition with the forwarded query.

17. 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 in association with a database query within a distributed database system;

store the received logical table definition to the memory;

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 a local logical table definition;

determine whether the received logical table definition matches the local logical table definition, where, in being programmed to determine whether the received logical table definition matches the 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; and

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

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 the column name match and the 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; and

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

18. The system of claim 17, where, in being programmed to forward the query to at least one other distributed database node, the processor is programmed to forward the local logical table definition with the forwarded query.

19. The system of claim 17, where, in being programmed to forward the query to at least one other distributed database node, the processor is programmed to forward the received logical table definition with the forwarded query.

20. The system of claim 17, where the processor is further programmed to generate a warning when the local logical table definition does not match the received logical table definition and send the warning in response to the database query.