Composite Index
===============

Composite indexes are indexes that span multiple columns.

.. seealso::

    :ref:`composite-index`
      OpenAlchemy documentation for composite indexes.

    `SQLAlchemy Composite Index <https://docs.sqlalchemy.org/en/13/core/constraints.html#index-api>`_
      Documentation for defining composite indexes in SQLAlchemy.

The following example defines a composite index for the *Employee* schema over
the *name* and *division* property:

.. literalinclude:: ../../../examples/composite_index/example-spec.yml
    :language: yaml
    :linenos:

The following file uses OpenAlchemy to generate the SQLAlchemy models:

.. literalinclude:: ../../../examples/composite_index/models.py
    :language: python
    :linenos:

The SQLAlchemy models generated by OpenAlchemy are equivalent to the following
traditional models file:

.. literalinclude:: ../../../examples/composite_index/models_traditional.py
    :language: python
    :linenos:

OpenAlchemy will generate the following typed models:

.. literalinclude:: ../../../examples/composite_index/models_auto.py
    :language: python
    :linenos:

.. seealso::
    :ref:`getting-started`