====================
Black Hole Connector
====================

The Black Hole connector works like the /dev/null device file in the Linux operating system.
Metadata for any tables created via this connector is kept in memory and discarded when
Presto restarts. Tables are always empty, and any data written to them will be ignored.

Configuration
-------------

To configure the Black Hole connector, create a catalog properties file
``etc/catalog/blackhole.properties`` with the following contents:

.. code-block:: none

    connector.name=blackhole

Example usage
-------------

Create table using blackhole connector:

.. code-block:: sql

    CREATE TABLE blackhole.default.nation AS SELECT * from tpch.tiny.nation;

Insert data into table in blackhole connector:

.. code-block:: sql

    INSERT INTO blackhole.default.nation SELECT * FROM tpch.tiny.nation;

Read from blackhole connector:

.. code-block:: sql

    SELECT COUNT(*) FROM blackhole.default.nation;

====================
Black Hole Connector
====================

The Black Hole connector works like the ``/dev/null`` device on Unix-like
operating systems. Metadata for any tables created via this connector is
kept in memory on the coordinator and discarded when Presto restarts.
Tables are always empty, and any data written to them will be ignored.

.. warning::

    This connector will not work properly with multiple coordinators,
    since each coordinator will have a different metadata.

Configuration
-------------

To configure the Black Hole connector, create a catalog properties file
``etc/catalog/blackhole.properties`` with the following contents:

.. code-block:: none

    connector.name=blackhole

Examples
--------

Create a table using the blackhole connector::

    CREATE TABLE blackhole.test.nation AS
    SELECT * from tpch.tiny.nation;

Insert data into a table in the blackhole connector::

    INSERT INTO blackhole.test.nation
    SELECT * FROM tpch.tiny.nation;

Select from the blackhole connector::

    SELECT COUNT(*) FROM blackhole.test.nation;

The above query will always return ``0``.

Update documentation for Black Hole connector
Update documentation for Black Hole connector
