QUERYING SENSOR DATA STORED AS BINARY DECISION DIAGRAMS

• US 20120047160A1
• Filed: 08/17/2010
• Published: 02/23/2012
• Est. Priority Date: 08/17/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Stergiou, Stergios, Jain, Jawahar
• Granted Patent: US 8,930,394 B2
• Time in Patent Office: Days
• US Class Current: 707/769
• CPC Class Codes: G06F 16/9032 Query formulation
• CPC Class Codes: G06F 16/90335 Query processing

Abstract

According to certain embodiments, a search query for a search of samples of sensor data is received. The search query indicates one or more requested values of one or more data parameters. The samples are represented by a characteristic function indicating whether a given binary representation represents a sample. A query function representing the one or more requested values is formulated. The query function and the characteristic function are used to identify one or more samples that have the one or more requested values.

Claims

1. A method comprising:

receiving a search query for a search of a plurality of samples of sensor data, the search query indicating one or more requested values of one or more data parameters, the plurality of samples represented by a characteristic function indicating whether a given binary representation represents a sample of the plurality of samples;

formulating a query function representing the one or more requested values; and

using the query function and the characteristic function to identify one or more samples that have the one or more requested values.

2. The method of claim 1, a parameter of the one or more parameters representing a sensor measurement, a time, a temperature, or a location.

3. The method of claim 1, the formulating the query function further comprising:

expressing each requested value as a requested minterm to yield one or more requested minterms; and

formulating a query function from the one or more requested minterms.

4. The method of claim 1, the using the query function and the characteristic function further comprising:

applying a logical AND operation to the query function and the characteristic function.

5. The method of claim 1, further comprising:

determining the number of samples that have the one or more requested values.

6. The method of claim 1, the sensor data recording a plurality of measurements taken by one or more sensors.

7. The method of claim 1, the sensor data recording medical data or environmental data.

8. An apparatus comprising:

a memory configured to store a search query for a search of a plurality of samples of sensor data, the search query indicating one or more requested values of one or more data parameters, the plurality of samples represented by a characteristic function indicating whether a given binary representation represents a sample of the plurality of samples;

one or more processors configured to;

formulate a query function representing the one or more requested values; and

use the query function and the characteristic function to identify one or more samples that have the one or more requested values.

9. The apparatus of claim 8, a parameter of the one or more parameters representing a sensor measurement, a time, a temperature, or a location.

10. The apparatus of claim 8, the formulating the query function further comprising:

expressing each requested value as a requested minterm to yield one or more requested minterms; and

formulating a query function from the one or more requested minterms.

11. The apparatus of claim 8, the using the query function and the characteristic function further comprising:

applying a logical AND operation to the query function and the characteristic function.

12. The apparatus of claim 8, the one or more processors further configured to:

determine the number of samples that have the one or more requested values.

13. The apparatus of claim 8, the sensor data recording a plurality of measurements taken by one or more sensors.

14. The apparatus of claim 8, the sensor data recording medical data or environmental data.

15. One or more non-transitory computer-readable media storing code, when executed by one or more processors, configured to:

receive a search query for a search of a plurality of samples of sensor data, the search query indicating one or more requested values of one or more data parameters, the plurality of samples represented by a characteristic function indicating whether a given binary representation represents a sample of the plurality of samples;

formulate a query function representing the one or more requested values; and

use the query function and the characteristic function to identify one or more samples that have the one or more requested values.

16. The media of claim 15, a parameter of the one or more parameters representing a sensor measurement, a time, a temperature, or a location.

17. The media of claim 15, the formulating the query function further comprising:

expressing each requested value as a requested minterm to yield one or more requested minterms; and

formulating a query function from the one or more requested minterms.

18. The media of claim 15, the using the query function and the characteristic function further comprising:

applying a logical AND operation to the query function and the characteristic function.

19. The media of claim 15, the code further configured to:

determine the number of samples that have the one or more requested values.

20. The media of claim 15, the sensor data recording a plurality of measurements taken by one or more sensors.

21. The media of claim 15, the sensor data recording medical data or environmental data.