5.18. Redshift Connector

The Redshift connector allows querying and creating tables in anexternal Amazon Redshift cluster. This can be used to join data betweendifferent systems like Redshift and Hive, or between two differentRedshift clusters.

Configuration

To configure the Redshift connector, create a catalog properties filein etc/catalog named, for example, redshift.properties, tomount the Redshift connector as the redshift catalog.Create the file with the following contents, replacing theconnection properties as appropriate for your setup:

  1. connector.name=redshift
  2. connection-url=jdbc:postgresql://example.net:5439/database
  3. connection-user=root
  4. connection-password=secret

Multiple Redshift Databases or Clusters

The Redshift connector can only access a single database withina Redshift cluster. Thus, if you have multiple Redshift databases,or want to connect to multiple Redshift clusters, you must configuremultiple instances of the Redshift connector.

To add another catalog, simply add another properties file to etc/catalogwith a different name (making sure it ends in .properties). For example,if you name the property file sales.properties, Presto will create acatalog named sales using the configured connector.

Querying Redshift

The Redshift connector provides a schema for every Redshift schema.You can see the available Redshift schemas by running SHOW SCHEMAS:

  1. SHOW SCHEMAS FROM redshift;

If you have a Redshift schema named web, you can view the tablesin this schema by running SHOW TABLES:

  1. SHOW TABLES FROM redshift.web;

You can see a list of the columns in the clicks table in the web databaseusing either of the following:

  1. DESCRIBE redshift.web.clicks;
  2. SHOW COLUMNS FROM redshift.web.clicks;

Finally, you can access the clicks table in the web schema:

  1. SELECT * FROM redshift.web.clicks;

If you used a different name for your catalog properties file, usethat catalog name instead of redshift in the above examples.

Redshift Connector Limitations

The following SQL statements are not yet supported: