How to connect PolyBase to EnterpriseDB

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, and only for Standard SQL Server.

The CData ODBC drivers offer unmatched performance for interacting with live EnterpriseDB data using PolyBase due to optimized data processing built into the driver. When you issue complex SQL queries from SQL Server to EnterpriseDB, the driver pushes down supported SQL operations, like filters and aggregations, directly to EnterpriseDB 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 EnterpriseDB data, using a single query to pull data from distributed sources.

Connect to EnterpriseDB

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 EnterpriseDB Sys is created automatically).

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.

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

Create an External Data Source for EnterpriseDB 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 EnterpriseDB data.

NOTE: IDENTITY and SECRET correspond with the User and Password properties for EnterpriseDB.

CREATE DATABASE SCOPED CREDENTIAL enterprisedb_creds
WITH IDENTITY = 'enterprisedb_username', SECRET = 'enterprisedb_password';

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:

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

NOTE: SERVERNAME and PORT corresponds to the Server and Port connection properties for EnterpriseDB. PUSHDOWN is set to ON by default, meaning the ODBC Driver can leverage server-side processing for complex queries.

CREATE EXTERNAL DATA SOURCE cdata_enterprisedb_source
WITH ( 
  LOCATION = 'odbc://SERVERNAME[:PORT]',
  CONNECTION_OPTIONS = 'DSN=CData EnterpriseDB Sys',
  -- PUSHDOWN = ON | OFF,
  CREDENTIAL = enterprisedb_creds
);

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 the CData ODBC Driver for EnterpriseDB. 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 EnterpriseDB Orders would look similar to the following:

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

Having created external tables for EnterpriseDB 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 EnterpriseDB, freeing up local resources and computing power. Download a free, 30-day trial of the ODBC Driver for EnterpriseDB and start working with live EnterpriseDB data alongside your SQL Server data today.