Object Storage Service:Use Impala on an EMR cluster to query data stored in OSS-HDFS

Procedure

1. Log on to the E-MapReduce console. In the left-side navigation pane, click EMR on ECS and create an EMR cluster.

   When you create the EMR cluster, make sure that Product Version is EMR-3.46.2 or later, or EMR-5.12.2 or later, and Root Storage Directory of Cluster is set to an OSS-HDFS-enabled bucket. Use the defaults for other parameters. For details, see Create a cluster.

2. Run the following command on the terminal to connect to Impala.

   For more information, see Connect to Impala.

   impala-shell -i core-1-1

3. Use Impala to query data stored in OSS-HDFS.

   1. Create a database.

      CREATE DATABASE store LOCATION 'oss://<bucket-name>.<endpoint>/impala';

   2. Use the database.

      USE store;

   3. Create a table.

      CREATE EXTERNAL TABLE customer_demographics (
       `cd_demo_sk` INT,
       `cd_gender` STRING,
       `cd_marital_status` STRING,
       `cd_education_status` STRING,
       `cd_purchase_estimate` INT,
       `cd_credit_rating` STRING,
       `cd_dep_count` INT,
       `cd_dep_employed_count` INT,
       `cd_dep_college_count` INT)
      STORED AS PARQUET;

   4. Insert data into the table.

      INSERT INTO customer_demographics
      VALUES
        (1, 'Male', 'Single', 'Graduate', 1000, 'AAA', 2, 1, 1),
        (2, 'Female', 'Married', 'Undergraduate', 2000, 'BBB', 3, 2, 2);
      

   5. Query data in the table.

      select * from customer_demographics;