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Elastic Search Learning Notes More than 19 Field Sorting and String Sorting sort Multilevel ranking String sorting sort In order to sort by correlation, it is necessary to represent the correlation as a numerical value. In Elastic search, the correlation score is expressed by a floating point number and returned in the s ...

Extensible Markup Language (XML) is an extensible markup language designed to transfer and store data. Detailed information is available. http://www.w3school.com.cn/xml. HTML refers to Hyper Text Markup Language (HTML), which is the main tool for writing web pages on WWW. http://www.w3school.com.cn/html Both XML and HTML are ...

Why do we use arrays? When do we need to use arrays? 1. Grammar of arrays: Be careful: (1) When defining an array, the length of the space must be given. Once the length of the space is defined, it can not be modified. When the operation exceeds this length, the error of the array subscript crossing the boundary will be thrown ...

1 SparkSQL Introduction Spark SQL is a module Spark uses to process structured data. It provides a programming abstraction called DataFrame and serves as a distributed SQL query engine. Hive has been learned. It converts Hive SQL into MapReduce and submits it to cluster for execution. It greatly simplifies the complexity of pr ...

time data 2018-05-01 00:00:00.650 57 2018-05-01 00:00:01.990 54 2018-05-01 00:00:09.487 73 2018-05-01 00:00:14.607 95 2018-05-01 00:00:16.350 77 2018-05-01 00:00:16.397 28 2018-05-01 00:00:16.563 54 2018-05-01 00:00:25.457 19 2018-05-01 00:00:31.140 09 2018-05-01 00:00:54.427 18 2018- ...

Matplotlib is a Python 2-D Drawing Library, which generates publishing quality level graphics in various hard copy formats and cross-platform interactive environments [1]  . With Matplotlib, developers can generate drawings, histograms, power spectra, bar graphs, error graphs, scatter plots and so on with only a few lines of ...

Reference article: https://www.bbsmax.com/A/n2d9bqDvzD/   The corresponding Kafka version: kafka_2.12-2.0.0.jar, namely scala 2.12, kafka 2.0.0 version.   Note the kafka version and recommend 1.0.0 + version. We usually use the following way to query the group.id of all consumption:   kafka-consumer-groups.sh --bootstra ...

In production, the hdfs recycling bin must be open, usually set to 7 days. fs.trash.interval reserves time for the garbage collection station, and disables the function of the collection station if it is 0. The checkpoint time of fs.trash.checkpoint.interval recycling bin is generally set to be less than or equal to fs.trash.interval. If 0, t ...

Scala Quick Learning Manual 2 Category 1, Object, Inheritance, Characteristics Category 1.1 Definition of Class 1 //In Scala, classes do not need to be declared public. //Scala source files can contain multiple classes, all of which have public visibility. class Person { //The variable modified with val is a read-only pr ...

Hadoop 2.9.1 Install Hive 2.3.3 on Ubuntu 16.04 Preface http://hive.apache.org/downloads.html There are instructions. hadoop3.x Version needs hive3.0.0，and hadoop2.x Need hive2.3.3. Because of mine. hadoop It's 2..9，So choose to download hive2.3.3. Hive yes hadoop Tools, so you only need to install them NameNode Up, no need to install DataN ...