Connect to EnterpriseDB 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 EnterpriseDB, you get access to your EnterpriseDB data directly alongside your SQL Server data. This article describes creating an external data source and external tables to grant access to live EnterpriseDB 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 EnterpriseDB, allowing you to query data from EnterpriseDB 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 EnterpriseDB, leveraging server-side processing to return the requested EnterpriseDB data quickly.

Configure EnterpriseDB Connectivity for PolyBase

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

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

2. Select "EnterpriseDB" from the Add Connection panel

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

   The following connection properties are required in order to connect to data.

   • Server: The host name or IP of the server hosting the EnterpriseDB database.
   • Port: The port of the server hosting the EnterpriseDB database.

   You can also optionally set the following:

   • Database: The default database to connect to when connecting to the EnterpriseDB Server. If this is not set, the user's default database will be used.

   Connect Using Standard Authentication

   To authenticate using standard authentication, set the following:

   • User: The user which will be used to authenticate with the EnterpriseDB server.
   • Password: The password which will be used to authenticate with the EnterpriseDB server.

   Connect Using SSL Authentication

   You can leverage SSL authentication to connect to EnterpriseDB data via a secure session. Configure the following connection properties to connect to data:

   • SSLClientCert: Set this to the name of the certificate store for the client certificate. Used in the case of 2-way SSL, where truststore and keystore are kept on both the client and server machines.
   • SSLClientCertPassword: If a client certificate store is password-protected, set this value to the store's password.
   • SSLClientCertSubject: The subject of the TLS/SSL client certificate. Used to locate the certificate in the store.
   • SSLClientCertType: The certificate type of the client store.
   • SSLServerCert: The certificate to be accepted from the server.
   
4. Click Save & Test
5. Navigate to the Permissions tab in the Add EnterpriseDB 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 EnterpriseDB data from Polybase.

Create an External Data Source for EnterpriseDB 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 EnterpriseDB data.

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

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

Create an External Data Source for EnterpriseDB

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

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

Create External Tables for EnterpriseDB

After creating the external data source, use CREATE EXTERNAL TABLE statements to link to EnterpriseDB 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 EnterpriseDB Orders would look similar to the following.

CREATE EXTERNAL TABLE Orders(
  ShipName COLLATE [nvarchar](255) NULL,
  ShipCity COLLATE [nvarchar](255) NULL,
  ...
) WITH ( 
  LOCATION='EnterpriseDB1.EnterpriseDB.Orders',
  DATA_SOURCE=ConnectCloudInstance
);

Having created external tables for EnterpriseDB 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!