Data Definition Language (DDL) Migration

    This section focuses on the migration of the databases and tables from Teradata to Exasol. It includes information on how databases, data types, and constraints are mapped to Exasol.

    This migration guide is based on the premise of using the Teradata Database Migration Script to execute the DDL migration (schema, tables) and map all data types to Exasol data types. While it is possible to execute certain steps manually outside of the script, using the script lets you automate tasks for converting schemas and table definitions as much as possible.

    Prerequisite

    Before you begin with the migration, as a prerequisite you need to first upload Teradata JDBC driver to Exasol. To do this, you can follow the steps below: 

    1. You can download the JDBC driver (for example, terajdbc4.jar) from Teradata JDBC driver download site. Make sure you download the correct version of the JDBC driver matching the version of the Teradata database.
    2. Next, you need to upload this JDBC driver to EXAoperation, Exasol's management interface.
      1. Log in to the EXAoperation user interface as an administrator user.
      2. Select Configuration > Software and click the JDBC Drivers tab. Click Add to add the JDBC driver details.
      3. Enter the following details for the JDBC properties:
        • Driver Name: Teradata
        • Main Class: com.teradata.jdbc.TeraDriver
        • Prefix: jdbc:teradata:
        • Disable Security Manager: Do not select this option. This is an optional field. This allows the JDBC Driver to access the certificate and additional information.
        • Comment: This is an optional field.
      4. Click Add to save the settings.
      5. Select the radio button next to the driver from the list of JDBC drivers.
      6. Click Choose File to locate the downloaded driver and click Upload to upload the JDBC driver.
    3. Open your preferred Exasol SQL Client (for example, DBvisualizer or DBeaver) and create the connection to Teradata: 
      CREATE OR REPLACE CONNECTION TERADATA_DB 
      TO 'jdbc:teradata://192.168.99.105/CHARSET=UTF16' 
      USER 'dbc' IDENTIFIED BY 'dbc';

      4. It is important to set the correct CHARSET parameter, depending on your Teradata installation. You will get an error message similar to “String data right truncation”, if you used CHARSET=UTF8 instead of CHARSET=UTF16.

    4. Check the connection to your Teradata database from Exasol by performing a small dummy import, as shown below: 
      IMPORT FROM JDBC AT TERADATA_DB
      STATEMENT 'SELECT ''Connection to Teradata works''';

The next steps in the DDL migration are: