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***
API
***
The API is split into two modules: the ``multicorn`` module and the
`utils` module:
- The ``multicorn`` module contains the whole API needed for implementing
a Foreign Data Wrapper.
- The ``utils`` module contains logging and error reporting functions,
which are ultimately implemented as calls to the PostgreSQL API.
Implementing an FDW
===================
Implementing an FDW is as simple as implementing the
:py:class:`~multicorn.ForeignDataWrapper` class.
Required API
------------
.. py:currentmodule:: multicorn.ForeignDataWrapper
This subset of the API allows your ForeignDataWrapper to be used for read-only
queries.
You have to implement the following methods:
- :py:meth:`__init__`
- :py:meth:`execute`
.. note:: In the documentation, FDWs implementing this API will be marked with:
.. api_compat:: :read:
Write API
---------
To implement full write capabilites, the following property must be implemented:
.. autoattribute:: multicorn.ForeignDataWrapper.rowid_column
In addition to that, you should implement each DML operation as you see fit:
- :py:meth:`insert`
- :py:meth:`update`
- :py:meth:`delete`
.. note:: In the documentation, FDWs implementing this API will be marked with:
.. api_compat::
:write:
Transactional API
-----------------
Transactional Capabilities can be implemented with the following methods:
.. automethod:: multicorn.ForeignDataWrapper.begin
.. automethod:: multicorn.ForeignDataWrapper.pre_commit
.. automethod:: multicorn.ForeignDataWrapper.rollback
.. automethod:: multicorn.ForeignDataWrapper.sub_begin
.. automethod:: multicorn.ForeignDataWrapper.sub_commit
.. automethod:: multicorn.ForeignDataWrapper.sub_rollback
.. note:: In the documentation, FDWs implementing this API will be marked with:
.. api_compat::
:transaction:
Full API
========
.. autoclass:: multicorn.ForeignDataWrapper
:special-members: __init__
:members:
.. autoclass:: multicorn.SortKey
.. autoclass:: multicorn.Qual
:members:
.. autoclass:: multicorn.ColumnDefinition
:members:
.. autoclass:: multicorn.TableDefinition
:members:
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