Hive #

This documentation is a guide for using Paimon in Hive.

Version #

Paimon currently supports Hive 2.1, 2.1-cdh-6.3, 2.2, 2.3 and 3.1.

Execution Engine #

Paimon currently supports MR and Tez execution engine for Hive.

Installation #

Download the jar file with corresponding version.

You can also manually build bundled jar from the source code.

To build from source code, clone the git repository.

Build bundled jar with the following command. mvn clean install -DskipTests

You can find Hive connector jar in ./paimon-hive/paimon-hive-connector-<hive-version>/target/paimon-hive-connector-<hive-version>-0.4.0-incubating.jar.

There are several ways to add this jar to Hive.

• You can create an auxlib folder under the root directory of Hive, and copy paimon-hive-connector-0.4.0-incubating.jar into auxlib.
• You can also copy this jar to a path accessible by Hive, then use add jar /path/to/paimon-hive-connector-0.4.0-incubating.jar to enable paimon support in Hive. Note that this method is not recommended. If you’re using the MR execution engine and running a join statement, you may be faced with the exception org.apache.hive.com.esotericsoftware.kryo.kryoexception: unable to find class.

NOTE: If you are using HDFS, make sure that the environment variable HADOOP_HOME or HADOOP_CONF_DIR is set.

Quick Start with Paimon Hive Catalog #

By using paimon Hive catalog, you can create, drop and insert into paimon tables from Flink. These operations directly affect the corresponding Hive metastore. Tables created in this way can also be accessed directly from Hive.

Step 1: Prepare Flink Hive Connector Bundled Jar

See creating a catalog with Hive metastore.

Step 2: Create Test Data with Flink SQL

Execute the following Flink SQL script in Flink SQL client to define a Paimon Hive catalog and create a table.

-- Flink SQL CLI
-- Define paimon Hive catalog

CREATE CATALOG my_hive WITH (
  'type' = 'paimon',
  'metastore' = 'hive',
  'uri' = 'thrift://<hive-metastore-host-name>:<port>',
  'warehouse' = '/path/to/table/store/warehouse'
);

-- Use paimon Hive catalog

USE CATALOG my_hive;

-- Create a table in paimon Hive catalog (use "default" database by default)

CREATE TABLE test_table (
  a int,
  b string
);

-- Insert records into test table

INSERT INTO test_table VALUES (1, 'Table'), (2, 'Store');

-- Read records from test table

SELECT * FROM test_table;

/*
+---+-------+
| a |     b |
+---+-------+
| 1 | Table |
| 2 | Store |
+---+-------+
*/

Step 3: Query the Table in Hive

Run the following Hive SQL in Hive CLI to access the created table.

-- Assume that paimon-hive-connector-<hive-version>-0.4.0-incubating.jar is already in auxlib directory.
-- List tables in Hive
-- (you might need to switch to "default" database if you're not there by default)

SHOW TABLES;

/*
OK
test_table
*/

-- Read records from test_table

SELECT a, b FROM test_table ORDER BY a;

/*
OK
1	Table
2	Store
*/

Quick Start with External Table #

To access existing paimon table, you can also register them as external tables in Hive. Run the following Hive SQL in Hive CLI.

-- Assume that paimon-hive-connector-0.4.0-incubating.jar is already in auxlib directory.
-- Let's use the test_table created in the above section.
-- To create an external table, you don't need to specify any column or table properties.
-- Pointing the location to the path of table is enough.

CREATE EXTERNAL TABLE external_test_table
STORED BY 'org.apache.paimon.hive.PaimonStorageHandler'
LOCATION '/path/to/table/store/warehouse/default.db/test_table';

-- Read records from external_test_table

SELECT a, b FROM test_table ORDER BY a;

/*
OK
1	Table
2	Store
*/

Hive Type Conversion #

This section lists all supported type conversion between Hive and Flink. All Hive’s data types are available in package org.apache.hadoop.hive.serde2.typeinfo.