Quick Start

This tutorial provides a quick introduction to using CarbonData.

Prerequisites

  • Installation and building CarbonData.

  • Create a sample.csv file using the following commands. The CSV file is required for loading data into CarbonData.

    cd carbondata
    cat > sample.csv << EOF
    id,name,city,age
    1,david,shenzhen,31
    2,eason,shenzhen,27
    3,jarry,wuhan,35
    EOF
    

Interactive Analysis with Spark Shell Version 2.1

Apache Spark Shell provides a simple way to learn the API, as well as a powerful tool to analyze data interactively. Please visit Apache Spark Documentation for more details on Spark shell.

Basics

Start Spark shell by running the following command in the Spark directory:

./bin/spark-shell --jars <carbondata assembly jar path>

NOTE: Assembly jar will be available after building CarbonData and can be copied from ./assembly/target/scala-2.1x/carbondata_xxx.jar

In this shell, SparkSession is readily available as spark and Spark context is readily available as sc.

In order to create a CarbonSession we will have to configure it explicitly in the following manner :

  • Import the following :
import org.apache.spark.sql.SparkSession
import org.apache.spark.sql.CarbonSession._
  • Create a CarbonSession :
val carbon = SparkSession.builder().config(sc.getConf)
             .getOrCreateCarbonSession("<hdfs store path>")

NOTE: By default metastore location is pointed to ../carbon.metastore, user can provide own metastore location to CarbonSession like SparkSession.builder().config(sc.getConf) .getOrCreateCarbonSession("<hdfs store path>", "<local metastore path>")

Executing Queries

Creating a Table
scala>carbon.sql("CREATE TABLE
                        IF NOT EXISTS test_table(
                                  id string,
                                  name string,
                                  city string,
                                  age Int)
                       STORED BY 'carbondata'")
Loading Data to a Table
scala>carbon.sql("LOAD DATA INPATH '/path/to/sample.csv'
                  INTO TABLE test_table")

NOTE: Please provide the real file path of sample.csv for the above script. If you get "tablestatus.lock" issue, please refer to troubleshooting

Query Data from a Table
scala>carbon.sql("SELECT * FROM test_table").show()

scala>carbon.sql("SELECT city, avg(age), sum(age)
                  FROM test_table
                  GROUP BY city").show()