Slide 1Towards Sensor Database Systems [Bonnet+ 2001]Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Supporting Aggregate Queries Over Ad-Hoc Wireless Sensor Networks [Madden+ 2002]Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Sensor Data Management In Sensor NetworksI. IntroductionI. Introduction–This paper defines a model for sensor databasesThis paper defines a model for sensor databases–Stored data are represented as relations while sensor data are Stored data are represented as relations while sensor data are represented as time series and each long-running query formulated over represented as time series and each long-running query formulated over a sensor database defines a persistent view, which is maintained during a a sensor database defines a persistent view, which is maintained during a given time intervalgiven time interval–The design and implementation of the COUGAR sensor database system The design and implementation of the COUGAR sensor database system is also describedis also described–Applications monitor the world by querying and analyzing sensor dataApplications monitor the world by querying and analyzing sensor dataTowards Sensor Database Systems[Bonnet+ 2001]I. IntroductionI. Introduction–Examples of monitoring applications include Examples of monitoring applications include osupervising items in a factory warehouse, supervising items in a factory warehouse, ogathering information in a disaster area, gathering information in a disaster area, oorganizing vehicle traffic in a large cityorganizing vehicle traffic in a large city–These applications involve a combination of stored data (a list of sensors These applications involve a combination of stored data (a list of sensors and their related attributes, such as their location) and sensor dataand their related attributes, such as their location) and sensor data–These will be called These will be called sensor databasessensor databases–This paper focuses on sensor query processing – the design, algorithms, This paper focuses on sensor query processing – the design, algorithms, and implementations used to run queries over sensor databasesand implementations used to run queries over sensor databases–A A sensor querysensor query is defined as a query expressed over a sensor database is defined as a query expressed over a sensor databaseTowards Sensor Database Systems[Bonnet+ 2001]I. IntroductionI. IntroductionFactory Warehouse ExampleFactory Warehouse Example–A A sensor querysensor query is defined as a query expressed over a sensor database is defined as a query expressed over a sensor database–Each item of a factory warehouse has a stick-on temperature sensor Each item of a factory warehouse has a stick-on temperature sensor attached to it as well as other attached sensors are to walls and attached to it as well as other attached sensors are to walls and embedded in floors and ceilingsembedded in floors and ceilings–Each sensor provides two signal-processing functions:Each sensor provides two signal-processing functions:1.1.getTemperature()getTemperature() returns the measured temperature at regular intervals, and returns the measured temperature at regular intervals, and 2.2.detectAlarmTemperature(threshold)detectAlarmTemperature(threshold) returns the temperature whenever it returns the temperature whenever it crosses a certain thresholdcrosses a certain threshold–Each sensor is able to communicate this data and/or to store it locallyEach sensor is able to communicate this data and/or to store it locallyTowards Sensor Database Systems[Bonnet+ 2001]Factory Warehouse ExampleFactory Warehouse Example–The sensor database stores the identifier of all sensors in the warehouse The sensor database stores the identifier of all sensors in the warehouse along with their location and is connected to the sensor networkalong with their location and is connected to the sensor network–The sensor database is used to make sure that items do not overheatThe sensor database is used to make sure that items do not overheat–Typical queries that are run continuously may include:Typical queries that are run continuously may include:oQuery 1: “Return repeatedly the abnormal temperatures measured”Query 1: “Return repeatedly the abnormal temperatures measured”oQuery 2: “Every minute, return the temperature measured on the third floor”Query 2: “Every minute, return the temperature measured on the third floor”oQuery 3: “Generate a notification whenever two sensors within 5 yards of each Query 3: “Generate a notification whenever two sensors within 5 yards of each other simultaneously measure an abnormal temperature”other simultaneously measure an abnormal temperature”oQuery 4: “Every five minutes retrieve the maximum temperature measured Query 4: “Every five minutes retrieve the maximum temperature measured over the last five minutes”over the last five minutes”oQuery 5: “Return the average temperature measured on each floor over the Query 5: “Return the average temperature measured on each floor over the last 10 minutes”last 10 minutes”Towards Sensor Database Systems[Bonnet+ 2001]Factory Warehouse ExampleFactory Warehouse Example–These examples queries have the following characteristics:These examples queries have the following characteristics:oMonitoring queries are long runningMonitoring queries are long runningoThe desired result of a query is typically a series of notifications of system The desired result of a query is typically a series of notifications of system activity (periodic or triggered by special situations)activity (periodic or triggered by special situations)oQueries need to correlate data produced simultaneously by different sensorsQueries need to correlate data produced simultaneously by different sensorsoQueries need to aggregate sensor data over time windowsQueries need to aggregate sensor data over time windowsoMost queries contain some condition restricting the set of sensors that are Most queries contain some condition restricting the set of sensors that are involved (usually geographical conditions)involved (usually geographical conditions)–Queries are formulated regardless of the
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