.. _version_4.5.0:

=============
Version 4.5.0
=============

Released on 2021-03-23.

.. NOTE::

    If you are upgrading a cluster, you must be running CrateDB 4.0.2 or higher
    before you upgrade to 4.5.0.

    We recommend that you upgrade to the latest 4.3 release before moving to
    4.5.0.

    A rolling upgrade from 4.3.x to 4.5.0 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:


Deprecations
============

- The table setting :ref:`sql-create-table-soft-deletes-enabled` has been
  marked as deprecated and will be removed in a future version. Soft deletes
  will become mandatory in CrateDB 5.0.


Changes
=======


Licensing
---------

- Relicensed all enterprise features under the Apache License 2.0 and removed
  licensing related code. The ``SET LICENSE`` statement can still be used, but
  it won't have any effect.

  Because of this, all users have now access to features like

  - :ref:`User management <administration_user_management>`.
  - :ref:`Authentication <admin_auth>` and :ref:`SSL/TLS support <admin_ssl>`.
  - :ref:`User defined function support <user-defined-functions>`.
  - :ref:`All window functions <window-functions>`.
  - :ref:`JMX monitoring features <jmx_monitoring>`.
  - The :ref:`hyperloglog_distinct aggregation function <aggregation-hyperloglog-distinct>`.


Performance improvements
------------------------

- Optimized how ``NULL`` values are stored, reducing the amount of disk space
  required. This can also improve the performance of value lookups on tables
  with a lot of null values.


SQL and PostgreSQL compatibility improvements
---------------------------------------------


- Added the ``regclass`` data type for improved compatibility with PostgreSQL
  tools.

- Added an empty ``pg_tablespace`` table in the ``pg_catalog`` schema for
  improved support for PostgreSQL tools.

- Improved the error messages for cast errors for values of type ``object``.

- Added support for the :ref:`CREATE TABLE AS <ref-create-table-as>` statement.


Administration and Operations
-----------------------------

- Added support for restoring metadata and settings from snapshots.  If ``ALL``
  is used, everything (tables, settings, views, etc.) will be restored. On the
  other hand, using ``TABLES`` will only restore tables.  In previous releases,
  only tables could be restored, even if ``ALL`` was used.

- Improved language selection, translations and general usability at the
  Admin UI.

- Updated the bundled JDK to 16+36


New scalar and window functions
-------------------------------

- Added the :ref:`gen_random_text_uuid() <scalar-gen_random_text_uuid>` scalar
  function.

- Added the :ref:`pg_postmaster_start_time() <scalar-pg_postmaster_start_time>`
  scalar function.

- Added :ref:`CURDATE <scalar-curdate>` and :ref:`CURRENT_DATE
  <scalar-current_date>` :ref:`scalar functions <scalar-functions>`.
