How to connect PolyBase to ADP

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 ADP, you get access to your ADP data directly alongside your SQL Server data. This article describes creating an external data source and external tables to grant access to live ADP 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 ADP data using PolyBase due to optimized data processing built into the driver. When you issue complex SQL queries from SQL Server to ADP, the driver pushes down supported SQL operations, like filters and aggregations, directly to ADP 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 ADP data, using a single query to pull data from distributed sources.

Connect to ADP

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 ADP Sys is created automatically).

Connect to ADP by specifying the following properties:

• SSLClientCert: Set this to the certificate provided during registration.
• SSLClientCertPassword: Set this to the password of the certificate.
• UseUAT: The connector makes requests to the production environment by default. If using a developer account, set UseUAT = true.
• RowScanDepth: The maximum number of rows to scan for the custom fields columns available in the table. The default value will be set to 100. Setting a high value may decrease performance.

The connector uses OAuth to authenticate with ADP. OAuth requires the authenticating user to interact with ADP using the browser. For more information, refer to the OAuth section in the Help documentation.

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

Create an External Data Source for ADP 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 ADP data.

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

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

Create an External Data Source for ADP

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

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

For ADP, 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_adp_source
WITH ( 
  LOCATION = 'odbc://SERVER_URL',
  CONNECTION_OPTIONS = 'DSN=CData ADP Sys',
  -- PUSHDOWN = ON | OFF,
  CREDENTIAL = adp_creds
);

Create External Tables for ADP

After creating the external data source, use CREATE EXTERNAL TABLE statements to link to ADP data from your SQL Server instance. The table column definitions must match those exposed by the CData ODBC Driver for ADP. 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 ADP Workers would look similar to the following:

CREATE EXTERNAL TABLE Workers(
  AssociateOID [nvarchar](255) NULL,
  WorkerID [nvarchar](255) NULL,
  ...
) WITH ( 
  LOCATION='Workers',
  DATA_SOURCE=cdata_adp_source
);

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