How to connect PolyBase to Linear

PolyBase for SQL Server allows you to query external data by using the same Transact-SQL syntax used to query a database table. When paired with the CData ODBC Driver for Linear, you get access to your Linear data directly alongside your SQL Server data. This article describes creating an external data source and external tables to grant access to live Linear data using T-SQL queries.

NOTE: PolyBase is only available on SQL Server 19 and above.

The CData ODBC drivers offer unmatched performance for interacting with live Linear data using PolyBase due to optimized data processing built into the driver. When you issue complex SQL queries from SQL Server to Linear, the driver pushes down supported SQL operations, like filters and aggregations, directly to Linear and utilizes the embedded SQL engine to process unsupported operations (often SQL functions and JOIN operations) client-side. And with PolyBase, you can also join SQL Server data with Linear data, using a single query to pull data from distributed sources.

Connect to Linear

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs. To create an external data source in SQL Server using PolyBase, configure a System DSN (CData Linear Sys is created automatically).

You can authenticate to Linear with a personal API key or with OAuth 2.0. The API key is the simplest option for connecting with your own Linear account.

Authenticating with an API Key

Set the following connection properties:

• AuthScheme: Set this to APIKey.
• APIKey: A Linear personal API key.

To create a personal API key, log in to Linear, open Settings > Security & access > Personal API keys, select New API key, and create it. Copy the key immediately, because Linear shows it only once.

Authenticating with OAuth

OAuth requires a custom OAuth application registered in Linear (Settings > API > OAuth applications), which provides the OAuthClientId and OAuthClientSecret. Two flows are supported:

• Authorization code: Set AuthScheme to OAuth, InitiateOAuth to GETANDREFRESH, and provide OAuthClientId, OAuthClientSecret, and the CallbackURL defined in your application (e.g., http://localhost:33333). The driver opens Linear in your browser so you can grant access.
• Client credentials: Set AuthScheme to OAuthClient and provide OAuthClientId and OAuthClientSecret. This authenticates the application itself, with no browser interaction, and suits machine-to-machine integrations.

By default, the driver requests the read,write scopes. The driver refreshes the access token automatically when it expires.

Click "Test Connection" to ensure that the DSN is connected to Linear properly. Navigate to the Tables tab to review the table definitions for Linear.

Create an External Data Source for Linear Data

After configuring the connection, you need to create a master encryption key and a credential database for the external data source.

Creating a Master Encryption Key

Execute the following SQL command to create a new master key, 'ENCRYPTION,' to encrypt the credentials for the external data source.

CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'password';

Creating a Credential Database

Execute the following SQL command to create credentials for the external data source connected to Linear data.

NOTE: Since Linear does not require a User or Password to authenticate, you may use whatever values you wish for IDENTITY and SECRET.

CREATE DATABASE SCOPED CREDENTIAL linear_creds
WITH IDENTITY = 'username', SECRET = 'password';

Create an External Data Source for Linear

Execute a CREATE EXTERNAL DATA SOURCE SQL command to create an external data source for Linear with PolyBase:

• Set the LOCATION parameter , using the DSN and credentials configured earlier.

For Linear, set SERVERNAME to the URL or address for your server (e.g. 'localhost' or '127.0.0.1' for local servers; the remote URL for remote servers). Leave PORT empty. PUSHDOWN is set to ON by default, meaning the ODBC Driver can leverage server-side processing for complex queries.

CREATE EXTERNAL DATA SOURCE cdata_linear_source
WITH ( 
  LOCATION = 'odbc://SERVER_URL',
  CONNECTION_OPTIONS = 'DSN=CData Linear Sys',
  -- PUSHDOWN = ON | OFF,
  CREDENTIAL = linear_creds
);

Create External Tables for Linear

After creating the external data source, use CREATE EXTERNAL TABLE statements to link to Linear data from your SQL Server instance. The table column definitions must match those exposed by the CData ODBC Driver for Linear. You can refer to the Tables tab of the DSN Configuration Wizard to see the table definition.

Sample CREATE TABLE Statement

The statement to create an external table based on a Linear Team would look similar to the following:

CREATE EXTERNAL TABLE Team(
  id [nvarchar](255) NULL,
  name [nvarchar](255) NULL,
  ...
) WITH ( 
  LOCATION='Team',
  DATA_SOURCE=cdata_linear_source
);

Having created external tables for Linear in your SQL Server instance, you are now able to query local and remote data simultaneously. Thanks to built-in query processing in the CData ODBC Driver, you know that as much query processing as possible is being pushed to Linear, freeing up local resources and computing power. Download a free, 30-day trial of the ODBC Driver for Linear and start working with live Linear data alongside your SQL Server data today.