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Database and table building --Build database create database test; --Build table create table student(s_id string,s_name string,s_birth string,s_sex string) row format delimited fields terminated by '\t'; create table course(c_id string,c_name string,t_id string) row format delimited fields terminated by '\t'; create table teacher(t_id string ...

1. Problem description After joining the new company, the author found that hive itself did not support Chinese annotations and was garbled when he was preparing to build the data warehouse, because the current big data started late and the data warehouse was still in the primary construction stage. The cluster was built with CDH 5.10.0. show ...

Summary of common HIVE functions There are many hive functions. In the past, it was always used and checked. Today, I will summarize the commonly used functions for easy reference in the future. This paper mainly involves the following aspects: 1. Hive function introduction and built-in function view See Hive official documents for more i ...

query 1. Data preparation 1.1 create table // Create department table create table if not exists dept ( deptno int, dname string, loc int ) row format delimited fields terminated by '\t'; // Create employee table create table if not exists emp ( empno int, ename string, job string, mgr int, hiredate string, ...

1, Introduction to e-commerce business 1.1 e-commerce business process The business process of e-commerce can be illustrated by taking the browsing footprint of an ordinary user as an example. Users click the home page of e-commerce to start browsing. They may find their favorite products through classified query or full-text search. Thes ...

Chapter 1 basic concepts of Impala 1.1 what is Impala Cloudera provides interactive SQL query function with high performance and low latency for HDFS and HBase data. Based on Hive, it uses memory computing, takes into account data warehouse, and has the advantages of real-time, batch processing, multi concurrency and so on. It is the prefer ...

1 data tilt Most tasks are completed quickly, and only one or a few tasks are executed slowly or even fail. This phenomenon is data skew.The data skew is divided into single table query with GroupBy field and two table (or multi table) Join query. 1.1 single table data skew optimization 1.1.1 the map side performs aggregation - GroupBy opera ...

Introduction to Presto Presto is a distributed SQL query engine developed by Facebook for efficient and real-time data analysis.Presto can connect Hive, Mysql, Kafka and other data sources. The most common way to connect Hive data sources is through Presto, which can solve the problem that Hive's MapReduce query takes too long.Presto is a ...

Welcome to the blog home page: Wechat search: Import_ Bigdata, hard core original author in big data field_ import_bigdata_ CSDN blog Welcome to like, collect, leave messages, and exchange messages!This article was originally written by [Wang Zhiwu] and started on CSDN blog!This article is the first CSDN forum. It is strictly prohibited to ...

Welcome to the blog home page: Wechat search: Import_ Bigdata, hard core original author in big data field_ import_bigdata_ CSDN blog Welcome to like, collect, leave messages, and exchange messages!This article was originally written by [Wang Zhiwu] and started on CSDN blog!This article is the first CSDN forum. It is strictly prohibited to repr ...