Access Amazon Athena Data as a Remote Oracle Database

The Oracle Database Gateway for ODBC and Heterogeneous Services technology enable you to connect to ODBC data sources as remote Oracle databases. This article shows how to use the CData ODBC Driver for Amazon Athena to create a database link from Amazon Athena to Oracle and to query Amazon Athena data through the SQL*Plus tool. You can also create the database link and execute queries from SQL Developer.

Getting Started

---

Connect to Amazon Athena as an ODBC Data Source

Information for connecting to Amazon Athena follows, along with different instructions for configuring a DSN in Windows and Linux environments.

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 to the access key Id. Set 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 to true and leave and 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 . 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 and of an IAM user to assume the role for. Roles may not be used when specifying the and of an AWS root user.

Authenticating with MFA

For users and roles that require Multi-factor Authentication, specify the and 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 (default 3600 seconds).

Connecting to Amazon Athena

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

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

Windows

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.

Note: If you need to modify the DSN or create other Amazon Athena DSNs, you must use a system DSN and the bitness of the DSN must match your Oracle system. You can access and create 32-bit DSNs on a 64-bit system by opening the 32-bit ODBC Data Source Administrator from C:\Windows\SysWOW64\odbcad32.exe.

Linux

If you are installing the CData ODBC Driver for Amazon Athena in a Linux environment, the driver installation predefines a system DSN. You can modify the DSN by editing the system data sources file (/etc/odbc.ini) and defining the required connection properties.

/etc/odbc.ini

[CData AmazonAthena Source]
Driver = CData ODBC Driver for Amazon Athena
Description = My Description
AWSAccessKey = 'a123'
AWSSecretKey = 's123'
AWSRegion = 'IRELAND'
Database = 'sampledb'
S3StagingDirectory = 's3://bucket/staging/'

For specific information on using these configuration files, please refer to the help documentation (installed and found online).

Set Connection Properties for Compatibility with Oracle

The driver provides several connection properties that streamline accessing Amazon Athena data just as you would an Oracle database. Set the following properties when working with Amazon Athena data in SQL*Plus and SQL Developer. For compatibility with Oracle, you will need to set the following connection properties, in addition to authentication and other required connection properties.

• MapToWVarchar=False

  Set this property to map string data types to SQL_VARCHAR instead of SQL_WVARCHAR. By default, the driver uses SQL_WVARCHAR to accommodate various international character sets. You can use this property to avoid the ORA-28528 Heterogeneous Services data type conversion error when the Unicode type is returned.

• MaximumColumnSize=4000

  Set this property to restrict the maximum column size to 4000 characters.

• IncludeDualTable=True

  Set this property to mock the Oracle DUAL table. SQL Developer uses this table to test the connection.

Linux Configuration

In Linux environments, Oracle uses UTF-8 to communicate with the unixODBC Driver manager, whereas the default driver encoding is UTF-16. To resolve this, open the file /opt/cdata/cdata-driver-for-amazonathena/lib/cdata.odbc.amazonathena.ini in a text editor and set the encoding.

cdata.odbc.amazonathena.ini

[Driver]
DriverManagerEncoding = UTF-8

Configure the ODBC Gateway, Oracle Net, and Oracle Database

Follow the procedure below to set up an ODBC gateway to Amazon Athena data that enables you to query live Amazon Athena data as an Oracle database.

1. Create the file initmyathenadb.ora in the folder oracle-home-directory/hs/admin and add the following setting:

   initmyathenadb.ora

   HS_FDS_CONNECT_INFO = "CData AmazonAthena Sys"

2. Add an entry to the listener.ora file. This file is located in oracle-home-directory/NETWORK/admin.

   If you are using the Database Gateway for ODBC, your listener.ora needs to have a SID_LIST_LISTENER entry that resembles the following:

   listener.ora

   SID_LIST_LISTENER =
    (SID_LIST =
    (SID_DESC =
    (SID_NAME = myathenadb)
    (ORACLE_HOME = your-oracle-home)
    (PROGRAM = dg4odbc)
    )
    )
   

   If you are using Heterogeneous Services, your listener.ora needs to have a SID_LIST_LISTENER entry that resembles the following:

   listener.ora

   SID_LIST_LISTENER =
    (SID_LIST =
    (SID_DESC =
    (SID_NAME = myathenadb)
    (ORACLE_HOME = your-oracle-home)
    (PROGRAM = hsodbc)
    )
    )
   

3. Add the connect descriptor below in tnsnames.ora, located in oracle-home-directory/NETWORK/admin:

   tnsnames.ora

   myathenadb =
    (DESCRIPTION=
    (ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1521))
    (CONNECT_DATA=(SID=myathenadb))
    (HS=OK)
    ) 
   

4. Restart the listener.

5. Test the configuration with the following command:

   tnsping myathenadb

6. Open SQL*Plus and create the database link with the command below:

   CREATE DATABASE LINK myathenadb CONNECT TO "user" IDENTIFIED BY "password" USING 'myathenadb';

You can now execute queries in SQL*Plus like the one below (note the double quotation marks around the table name):

SELECT * from "Customers"@myathenadb WHERE CustomerId = '12345';