A PostgreSQL Interface for Amazon Athena Data

There are a vast number of PostgreSQL clients available on the Internet. From standard Drivers to BI and Analytics tools, PostgreSQL is a popular interface for data access. Using our JDBC Drivers, you can now create PostgreSQL entry-points that you can connect to from any standard client.

To access Amazon Athena data as a PostgreSQL database, use the CData JDBC Driver for Amazon Athena and a JDBC foreign data wrapper (FDW). In this article, we compile the FDW, install it, and query Amazon Athena data from PostgreSQL Server.

Connect to Amazon Athena Data as a JDBC Data Source

To connect to Amazon Athena as a JDBC data source, you will need the following:

• Driver JAR path: The JAR is located in the lib subfolder of the installation directory.

• Driver class: cdata.jdbc.amazonathena.AmazonAthenaDriver

• JDBC URL: The URL must start with "jdbc:amazonathena:" and can include any of the connection properties in name-value pairs separated with semicolons.

  Authenticating to Amazon Athena

  To authorize Amazon Athena requests, provide the credentials for an administrator account or for an IAM user with custom permissions: Set AccessKey to the access key Id. Set SecretKey to the secret access key.

  Note: Though you can connect as the AWS account administrator, it is recommended to use IAM user credentials to access AWS services.

  Obtaining the Access Key

  To obtain the credentials for an IAM user, follow the steps below:

  1. Sign into the IAM console.
  2. In the navigation pane, select Users.
  3. To create or manage the access keys for a user, select the user and then select the Security Credentials tab.

  To obtain the credentials for your AWS root account, follow the steps below:

  1. Sign into the AWS Management console with the credentials for your root account.
  2. Select your account name or number and select My Security Credentials in the menu that is displayed.
  3. Click Continue to Security Credentials and expand the Access Keys section to manage or create root account access keys.

  Authenticating from an EC2 Instance

  If you are using the CData Data Provider for Amazon Athena 2018 from an EC2 Instance and have an IAM Role assigned to the instance, you can use the IAM Role to authenticate. To do so, set UseEC2Roles to true and leave AccessKey and SecretKey empty. The CData Data Provider for Amazon Athena 2018 will automatically obtain your IAM Role credentials and authenticate with them.

  Authenticating as an AWS Role

  In many situations it may be preferable to use an IAM role for authentication instead of the direct security credentials of an AWS root user. An AWS role may be used instead by specifying the RoleARN. This will cause the CData Data Provider for Amazon Athena 2018 to attempt to retrieve credentials for the specified role. If you are connecting to AWS (instead of already being connected such as on an EC2 instance), you must additionally specify the AccessKey and SecretKey of an IAM user to assume the role for. Roles may not be used when specifying the AccessKey and SecretKey of an AWS root user.

  Authenticating with MFA

  For users and roles that require Multi-factor Authentication, specify the MFASerialNumber and MFAToken connection properties. This will cause the CData Data Provider for Amazon Athena 2018 to submit the MFA credentials in a request to retrieve temporary authentication credentials. Note that the duration of the temporary credentials may be controlled via the TemporaryTokenDuration (default 3600 seconds).

  Connecting to Amazon Athena

  In addition to the AccessKey and SecretKey properties, specify Database, S3StagingDirectory and Region. Set Region to the region where your Amazon Athena data is hosted. Set S3StagingDirectory to a folder in S3 where you would like to store the results of queries.

  If Database is not set in the connection, the data provider connects to the default database set in Amazon Athena.

  Built-in Connection String Designer

  For assistance in constructing the JDBC URL, use the connection string designer built into the Amazon Athena JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

  java -jar cdata.jdbc.amazonathena.jar

  Fill in the connection properties and copy the connection string to the clipboard.

  A typical JDBC URL is below:

  jdbc:amazonathena:AccessKey='a123';SecretKey='s123';Region='IRELAND';Database='sampledb';S3StagingDirectory='s3://bucket/staging/';

Build the JDBC Foreign Data Wrapper

The Foreign Data Wrapper can be installed as an extension to PostgreSQL, without recompiling PostgreSQL. The jdbc2_fdw extension is used as an example (downloadable here).

1. Add a symlink from the shared object for your version of the JRE to /usr/lib/libjvm.so. For example: ln -s /usr/lib/jvm/java-6-openjdk/jre/lib/amd64/server/libjvm.so /usr/lib/libjvm.so
2. Start the build: make install USE_PGXS=1

Query Amazon Athena Data as a PostgreSQL Database

After you have installed the extension, follow the steps below to start executing queries to Amazon Athena data:

1. Log into your database.
2. Load the extension for the database: CREATE EXTENSION jdbc2_fdw;
3. Create a server object for Amazon Athena: CREATE SERVER AmazonAthena FOREIGN DATA WRAPPER jdbc2_fdw OPTIONS ( drivername 'cdata.jdbc.amazonathena.AmazonAthenaDriver', url 'jdbc:amazonathena:AccessKey='a123';SecretKey='s123';Region='IRELAND';Database='sampledb';S3StagingDirectory='s3://bucket/staging/';', querytimeout '15', jarfile '/home/MyUser/CData/CData\ JDBC\ Driver\ for\ Salesforce MyDriverEdition/lib/cdata.jdbc.amazonathena.jar');
4. Create a user mapping for the username and password of a user known to the MySQL daemon. CREATE USER MAPPING for postgres SERVER AmazonAthena OPTIONS ( username 'admin', password 'test');
5. Create a foreign table in your local database: postgres=# CREATE FOREIGN TABLE customers ( customers_id text, customers_Name text, customers_TotalDue numeric) SERVER AmazonAthena OPTIONS ( table_name 'customers');