Foreign Data Wrapper (FDW) that facilitates access to Cassandra 2.x and 3.x from within PostgreSQL.

Cassandra: http://cassandra.apache.org/

PostgreSQL Support:

Cassandra Support:

Firstly, the latest Cassandra2 cpp driver needs be installed from https://github.com/datastax/cpp-driver.

You'll need the following packages to be installed with either, apt, or rpm, depending on your Linux distribution

• postgresql-server
• postgresql-contrib
• postgresql-server-dev-{version number}

# Clone the repository from GitHub
git clone https://github.com/jaiminpan/cassandra2_fdw

cd cassandra2_fdw
USE_PGXS=1 make
sudo USE_PGXS=1 make install 

The following parameters can be set on a Cassandra foreign server object:

• host: the address or host name of the Cassandra server, Examples: "127.0.0.1" "127.0.0.1,127.0.0.2", "server1.domain.com"
• port: the port number of the Cassandra server. Defaults is 9042
• protocol: the protocol connect to Cassandra server. Defaults depends on cassandra-cpp-driver. (Default is "2" of v2.1.0 and default is "4" of v2.2.2)

The following parameters can be set on a Cassandra foreign table object:

• schema_name: the name of the Cassandra keyspace to query. Defaults to public
• table_name: the name of the Cassandra table to query. Defaults to the foreign table name used in the relevant CREATE command

Here is an example

	-- Create the extension inside a database
	CREATE EXTENSION cassandra2_fdw;

	-- Create the server object
	CREATE SERVER cass_serv FOREIGN DATA WRAPPER cassandra2_fdw 
		OPTIONS(host '127.0.0.1,127.0.0.2', port '9042', protocol '2');

	-- Create a user mapping for the server
	CREATE USER MAPPING FOR public SERVER cass_serv OPTIONS(username 'test', password 'test');


	-- Create a foreign table on the server
	CREATE FOREIGN TABLE test (id int) SERVER cass_serv OPTIONS (schema_name 'example', table_name 'oorder');

	-- Query the foreign table
	SELECT * FROM test limit 5;

Unsupported data types will return an info text, that the data type is not supported instead of data.

• list: Not implemented in this FDW
• map: Not implemented in this FDW
• user defined types: Not implemented in the cpp-driver

With cpp-driver 2.16.0 against mentioned PostgreSQL versions and against Cassandra 3.2.

• Jaimin Pan
• Stefanie Janine Stölting