XXHASH_64

Description

Calculates the 64-bit xxhash value of the input string or binary.

-Note: After testing, the performance of xxhash_64 is about twice that of murmur_hash3_64, so when calculating hash values, it is recommended to use xxhash_64 instead of murmur_hash3_64.

Syntax

XXHASH_64( <input> [ , <input> ... ] )

Parameters

parameter	description
<input>	The 64-bit xxhash value to be calculated, accept string and binary types

Return Value

Returns the 64-bit xxhash value of the input string.

Examples

select xxhash_64(NULL), xxhash_64("hello"), xxhash_64("hello", "world");

+-----------------+----------------------+-----------------------------+
| xxhash_64(NULL) | xxhash_64('hello')   | xxhash_64('hello', 'world') |
+-----------------+----------------------+-----------------------------+
|            NULL | -7685981735718036227 |         7001965798170371843 |
+-----------------+----------------------+-----------------------------+

-- vb (VarBinary) and vc (VarChar) used the same string during insertion.
SELECT * FROM mysql_catalog.binary_test.binary_test;

+------+------------+------+
| id   | vb         | vc   |
+------+------------+------+
|    1 | 0x616263   | abc  |
|    2 | 0x78797A   | xyz  |
|    3 | NULL       | NULL |
+------+------------+------+

SELECT XXHASH_64(vb), XXHASH_64(vc) FROM mysql_catalog.binary_test.binary_test;

+---------------------+---------------------+
| XXHASH_64(vb)       | XXHASH_64(vc)       |
+---------------------+---------------------+
| 8696274497037089104 | 8696274497037089104 |
| 7095089596068863775 | 7095089596068863775 |
|                NULL |                NULL |
+---------------------+---------------------+