Redshift Connector

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

Configuration

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

connector.name=redshift
connection-url=jdbc:redshift://example.net:5439/database
connection-user=root
connection-password=secret

Multiple Redshift Databases or Clusters

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

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

General Configuration Properties

Property Name

Description

Default

user-credential-name

Name of the extraCredentials property whose value is the JDBC driver’s user name. See extraCredentials in Parameter Reference.

password-credential-name

Name of the extraCredentials property whose value is the JDBC driver’s user password. See extraCredentials in Parameter Reference.

case-insensitive-name-matching

Match dataset and table names case-insensitively.

false

case-insensitive-name-matching.cache-ttl

Duration for which remote dataset and table names will be cached. Set to 0ms to disable the cache.

1m

list-schemas-ignored-schemas

List of schemas to ignore when listing schemas.

information_schema

case-sensitive-name-matching

Enable case sensitive identifier support for schema and table names for the connector. When disabled, names are matched case-insensitively using lowercase normalization.

false

Procedures

Use the CALL statement to perform data manipulation or administrative tasks. Procedures are available in the system schema of the catalog.

Execute Procedure

Underlying datasources may support some operation or SQL syntax which is not supported by Presto, either at the parser level or at the connector level. Trying to run such SQL statements in Presto can result in errors during parsing or analysing. For example, Redshift supports creating auto generated primary keys which is not supported in Presto. Running this procedure enables users to do a SQL passthrough to the underlying database, and Presto just acts as a middle man for passing the statement.

The following arguments are available:

Argument Name

Required

Type

Description

QUERY

Yes

string

SQL statement to run

Examples:

  • Create a table with auto generated primary key:

    CALL redshift.system.execute('create table schema1.table1 (id INT IDENTITY(1, 1), a int)')

CALL redshift.system.execute(QUERY => 'create table schema1.table1 (id INT IDENTITY(1, 1), a int)')

Querying Redshift

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

SHOW SCHEMAS FROM redshift;

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

SHOW TABLES FROM redshift.web;

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

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

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

SELECT * FROM redshift.web.clicks;

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

Redshift Connector Limitations

The following SQL statements are not yet supported: