Requirements
============

To use pglogical the provider and subscriber must be running PostgreSQL
9.4 or newer.

The ``pglogical`` extension must be installed on both provider and
subscriber. You must ``CREATE EXTENSION pglogical`` on both.

Tables on the provider and subscriber must have the same names and be in
the same schema. Future revisions may add mapping features.

Tables on the provider and subscriber must have the same columns, with
the same data types in each column. ``CHECK`` constraints, ``NOT NULL``
constraints, etc., must be the same or weaker (more permissive) on the
subscriber than the provider.

Tables must have the same ``PRIMARY KEY`` s. It is not recommended to
add additional ``UNIQUE`` constraints other than the ``PRIMARY KEY``
(see below).

Some additional requirements are covered in :ref:`Limitations and restrictions <Limitations and restrictions>`  .