:orphan:

.. _crc64:

*****
CRC64
*****

The ``CRC64`` function calculates the CRC-64 hash of a text expression.

Syntax
======

.. code-block:: postgres

   CRC64( expr ) --> BIGINT

Arguments
=========

.. list-table:: 
   :widths: auto
   :header-rows: 1
   
   * - Parameter
     - Description
   * - ``expr``
     - Text expression (``TEXT``)

Returns
=======

Returns a CRC-64 hash of the text input, of type ``BIGINT``.

If the input value is ``NULL``, the result is ``NULL``.

Examples
========

.. code-block:: sql

   SELECT CRC64(x) FROM (VALUES ('This is a relatively long text string, that can be converted to a shorter hash' :: text)) as t(x);
 
.. code-block:: none

	-8397827068206190216