Connecting to SQream Using Trino

If you are using Trino for distributed SQL query processing and wish to use it to connect to a SQream, follow these instructions.

Prerequisites 

To use Trino with SQream, you must have the following installed:

SQream version 4.1 or later
Trino version 403 or later
Trino Connector xxxx
JDBC version 4.5.6 or later

Installation 

JDBC 

In case JDBC is not yet configured, follow the JDBC Client Drivers page for registration and configuration guidance.

Trino Connector 

The Trino Connector must be installed on each cluster node dedicated to Trino.

Create a dedicated directory for the Trino Connector.
Download the Trino Connector<…> and extract the content of the ZIP file to the dedicated directory, as shown in the example:

trino-server/
└── plugin
        └── sqream
                ├── sqream-jdbc.jar
                ├── trino-sqream-services.jar
                ├── trino-sqream-SNAPSHOT.jar
                └── all dependencies

Trino uses catalogs for referencing stored objects such as tables, databases, and functions. Each Trino catalog may be configured with access to a single SQream database. If you wish Trino to have access to more than one SQream database or server, you must create additional catalogs.

Catalogs may be created using properties files. Start by creating a sqream.properties file and placing it under trino-server/etc/catalog.

The following is an example of a properties file:

connector.name=<name>
connection-url=jdbc:Sqream://<host and port>/<database name>;[<optional parameters>; ...]
connection-user=<user>
connection-password=<password>

Syntax examples 

The following is an example of the SHOW SCHEMAS FROM statement:

SHOW SCHEMAS FROM sqream;

The following is an example of the SHOW TABLES FROM statement:

SHOW TABLES FROM sqream.public;

The following is an example of the DESCRIBE sqream.public.t statement:

DESCRIBE sqream.public.t;

Supported Data Types and Mapping 

Use the appropriate Trino data type for executing queries. Upon execution, incompatible data types will be converted by Trino to SQream data types.

Trino type	SQream type
`BOOLEAN`	`BOOL`
`TINYINT`	`TINYINT`
`SMALLINT`	`SMALLINT`
`INT`	`INT`
`BIGINT`	`BIGINT`
`REAL`	`REAL`
`DOUBLE`	`DOUBLE`
`DATE`	`DATE`
`TIMESTAMP`	`DATETIME`
`VARCHAR(N)`	`VARCHAR(N)`.
`VARCHAR`	`TEXT`
`DECIMAL(P,S)`	`NUMERIC(P,S)`

Note

VARCHAR is soon to be deprecated and may not be used in SQream DB.

Limitations 

The Trino Connector does not support the following SQL statements:

GRANT
REVOKE
SHOW GRANTSHOW ROLES
SHOW ROLE GRANTS