Query a SQL data source using the JdbcStorageHandler

Using the JdbcStorageHandler, you can connect Hive to a MySQL, PostgreSQL, Oracle, or Derby data source, create an external table to represent the data, and then query the table.

1. Load data into a supported SQL database, such as MySQL, on a node in your cluster or familiarize yourself with existing data in the your database.
2. Obtain credentials for accessing the database.
   • If you are accessing data on your network and have no security worries, you can use the user name and password that authorizes your to access Hive.
   • If you are accessing data on a remote network, create a JCEKS credential keystore on HDFS, and use credentials you specify in the process.
3. Create an external table using the JdbcStorageHandler and table properties that specify the minimum information: database type, driver, database connection string, user name and password for querying hive, table name, and number of active connections to Hive.

   CREATE EXTERNAL TABLE mytable_jdbc(
     col1 string,
     col2 int,
     col3 double
   )
   STORED BY 'org.apache.hive.storage.jdbc.JdbcStorageHandler'
   TBLPROPERTIES (
     "hive.sql.database.type" = "MYSQL",
     "hive.sql.jdbc.driver" = "com.mysql.jdbc.Driver",
     "hive.sql.jdbc.url" = "jdbc:mysql://localhost/sample",
     "hive.sql.dbcp.username" = "hive",
     "hive.sql.dbcp.password" = "hive",
     "hive.sql.table" = "MYTABLE",
     "hive.sql.dbcp.maxActive" = "1"
   );
4. Query the external table.

   SELECT * FROM mytable_jdbc WHERE col2 = 19;