.. _version_4.4.1:

=============
Version 4.4.1
=============

Released on 2021-02-03.

.. NOTE::

    If upgrading a cluster, you must be running CrateDB 4.0.2 or higher before
    you upgrade to 4.4.1.

    We recommend that you upgrade to the latest 4.3 release before moving to
    4.4.1.

    A rolling upgrade from 4.3.0+ to 4.4.1 is supported.

    Before upgrading, you should `back up your data`_.

.. _back up your data: https://crate.io/docs/crate/reference/en/latest/admin/snapshots.html



.. rubric:: Table of Contents

.. contents::
   :local:

See the :ref:`version_4.4.0` release notes for a full list of changes in the
4.4 series.

Fixes
=====

- Fixed an issue that could lead to stuck queries when joining more than two
  relations and if the WHERE clause contained filters on primary key columns
  that led to an execution plan using a ``primary key`` lookup on at least one
  relation.

- Fixed an issue in the PostgreSQL wire protocol implementation that could lead
  to incorrect results on the client side if a client invoked a write operation
  and sent an explicit flush message before the sync message. The
  ``node-postgres`` client is one client that uses such a message sequence.

- Fixed an issue that could lead to a ``stream has already been operated upon
  or closed`` error when using primary key lookup operations as part of a query
  with several JOIN clauses.

- Fixed a regression that caused queries which used a parameter placeholder in
  a join condition to fail with an ``The assembled list of ParameterSymbols is
  invalid. Missing parameters`` error.
