numeric time series. What summary would let us compute the statistical variance of this series? 3 var = ∑ (xi − μ)2 N ??? Vasiliki Kalavri | Boston University 2020 A simple and efficient synopsis Suppose the sum of all the values • the sum of the squares of the values • the number of observations var = ∑ (xi − μ)2 N ??? Vasiliki Kalavri | Boston University 2020 A simple and efficient synopsis Suppose the squares of the values • the number of observations • μ = sum / count • var = (sum of squares / count) - μ2 Then var = ∑ (xi − μ)2 N ??? Vasiliki Kalavri | Boston University 2020 A simple and

PeriodicAssigner extends AssignerWithPeriodicWatermarks[Reading] { val bound: Long = 60 * 1000 // 1 min in ms var maxTs: Long = Long.MinValue // the max observed timestamp override def getCurrentWatermark: Watermark

extends RichFlatMapFunction[Reading, (String, Double, Double)] { // the state handle object private var lastTempState: ValueState[Double] = _ override def open(parameters: Configuration): Unit = { // create

Python-3.7.9 && \ ln -s /usr/local/bin/python3 /usr/local/bin/python && \ apt-get clean && \ rm -rf /var/lib/apt/lists/* # install PyFlink RUN pip3 install apache-flink==1.15.2 Execute PyFlink jobs in application

Python-3.7.9 && \ ln -s /usr/local/bin/python3 /usr/local/bin/python && \ apt-get clean && \ rm -rf /var/lib/apt/lists/* # install PyFlink RUN pip3 install apache-flink==1.15.2 Execute PyFlink jobs in application