How to create Presto federated tables in MySQL

You can use the SQL Gateway to configure a MySQL remoting service and set up federated tables for Presto data. The service is a daemon process that provides a MySQL interface to the CData ODBC Driver for Presto: After you have started the service, you can create a server and tables using the FEDERATED Storage Engine in MySQL. You can then work with Presto data just as you would local MySQL tables.

Getting Started

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Connect to Presto Data

If you have not already done so, provide values for the required connection properties in the data source name (DSN). You can use the built-in Microsoft ODBC Data Source Administrator to configure the DSN. This is also the last step of the driver installation. See the "Getting Started" chapter in the help documentation for a guide to using the Microsoft ODBC Data Source Administrator to create and configure a DSN.

Set the Server and Port connection properties to connect, in addition to any authentication properties that may be required.

To enable TLS/SSL, set UseSSL to true.

Authenticating with LDAP

In order to authenticate with LDAP, set the following connection properties:

• AuthScheme: Set this to LDAP.
• User: The username being authenticated with in LDAP.
• Password: The password associated with the User you are authenticating against LDAP with.

Authenticating with Kerberos

In order to authenticate with KERBEROS, set the following connection properties:

• AuthScheme: Set this to KERBEROS.
• KerberosKDC: The Kerberos Key Distribution Center (KDC) service used to authenticate the user.
• KerberosRealm: The Kerberos Realm used to authenticate the user with.
• KerberosSPN: The Service Principal Name for the Kerberos Domain Controller.
• KerberosKeytabFile: The Keytab file containing your pairs of Kerberos principals and encrypted keys.
• User: The user who is authenticating to Kerberos.
• Password: The password used to authenticate to Kerberos.

Configure the SQL Gateway

See the SQL Gateway Overview to set up connectivity to Presto data as a virtual MySQL database. You will configure a MySQL remoting service that listens for MySQL requests from clients. The service can be configured in the SQL Gateway UI.

👁 Creating a MySQL Remoting Service in SQL Gateway (Salesforce is shown)

Create a FEDERATED Server and Tables for Presto Data

After you have configured and started the service, create a FEDERATED server to simplify the process of creating FEDERATED tables:

Create a FEDERATED Server

The following statement will create a FEDERATED server based on the ODBC Driver for Presto. Note that the username and password of the FEDERATED server must match a user account you defined on the Users tab of the SQL Gateway.

CREATE SERVER fedPresto
FOREIGN DATA WRAPPER mysql
OPTIONS (USER 'sql_gateway_user', PASSWORD 'sql_gateway_passwd', HOST 'sql_gateway_host', PORT ####, DATABASE 'CData Presto Sys');

Create a FEDERATED Table

To create a FEDERATED table using our newly created server, use the CONNECTION keyword and pass the name of the FEDERATED server and the remote table (Customer). Refer to the following template for the statement to create a FEDERATED table:

CREATE TABLE fed_customer (
 ...,
 firstname TYPE(LEN),
 lastname TYPE(LEN),
 ...,
)
ENGINE=FEDERATED
DEFAULT CHARSET=latin1
CONNECTION='fedPresto/customer';

NOTE: The table schema for the FEDERATED table must match the remote table schema exactly. You can always connect directly to the MySQL remoting service using any MySQL client and run a SHOW CREATE TABLE query to get the table schema.

Execute Queries

You can now execute queries to the Presto FEDERATED tables from any tool that can connect to MySQL, which is particularly useful if you need to JOIN data from a local table with data from Presto. Refer to the following example:

SELECT 
 fed_customer.firstname, 
 local_table.custom_field 
FROM 
 local_table 
JOIN 
 fed_customer 
ON 
 local_table.foreign_firstname = fed_customer.firstname;