Connect to Linear Data as an External Data Source using PolyBase

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.

CData Connect AI provides a pure SQL Server interface for Linear, allowing you to query data from Linear without replicating the data to a natively supported database. Using optimized data processing out of the box, CData Connect AI pushes all supported SQL operations (filters, JOINs, etc.) directly to Linear, leveraging server-side processing to return the requested Linear data quickly.

Configure Linear Connectivity for PolyBase

Connectivity to Linear from PolyBase is made possible through CData Connect AI. To work with Linear data from PolyBase, we start by creating and configuring a Linear connection.

1. Log into Connect AI, click Sources, and then click Add Connection

2. Select "Linear" from the Add Connection panel

3. Enter the necessary authentication properties to connect to Linear.

   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.

   
4. Click Save & Test
5. Navigate to the Permissions tab in the Add Linear Connection page and update the User-based permissions.

Add a Personal Access Token

When connecting to Connect AI through the REST API, the OData API, or the Virtual SQL Server, a Personal Access Token (PAT) is used to authenticate the connection to Connect AI. It is best practice to create a separate PAT for each service to maintain granularity of access.

1. Click on the Gear icon () at the top right of the Connect AI app to open the settings page.
2. On the Settings page, go to the Access Tokens section and click Create PAT.
3. Give the PAT a name and click Create.
4. The personal access token is only visible at creation, so be sure to copy it and store it securely for future use.

With the connection configured and a PAT generated, you are ready to connect to Linear data from Polybase.

Create an External Data Source for Linear Data

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

Creating a Credential Database

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

NOTE: Set IDENTITY to your Connect AI username and set SECRET to your Personal Access Token.

CREATE DATABASE SCOPED CREDENTIAL ConnectAICredentials
WITH IDENTITY = 'yourusername', SECRET = 'yourPAT';

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:

CREATE EXTERNAL DATA SOURCE ConnectAIInstance
WITH ( 
  LOCATION = 'sqlserver://tds.cdata.com:14333',
  PUSHDOWN = ON,
  CREDENTIAL = ConnectAICredentials
);

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 CData Connect AI. You can use the Data Explorer in Connect AI to see the table definition.

Sample CREATE TABLE Statement

Execute a CREATE EXTERNAL TABLE SQL command to create the external table(s), using the collation and setting the LOCATION to three-part notation for the connection, catalog, and table. The statement to create an external table based on a Linear Team would look similar to the following.

CREATE EXTERNAL TABLE Team(
  id COLLATE [nvarchar](255) NULL,
  name COLLATE [nvarchar](255) NULL,
  ...
) WITH ( 
  LOCATION='Linear1.Linear.Team',
  DATA_SOURCE=ConnectAIInstance
);

Having created external tables for Linear in your SQL Server instance, you are now able to query local and remote data simultaneously. To get live data access to hundreds of SaaS, Big Data, and NoSQL sources directly from your SQL Server database, try CData Connect AI today!