docs/sql-manual/sql-functions/hash-functions/xxhash-64.md

---
{
    "title": "XXHASH_64",
    "language": "en"
}
---

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## xxhash_64

### description
#### Syntax

`BIGINT XXHASH_64(VARCHAR input, ...)`

Return the 64 bits xxhash of input string.

Note: When calculating hash values, it is more recommended to use `xxhash_64` instead of `murmur_hash3_64`.

### example

```
mysql> select xxhash_64(NULL);
+-----------------+
| xxhash_64(NULL) |
+-----------------+
|            NULL |
+-----------------+

mysql> select xxhash_64("hello");
+----------------------+
| xxhash_64('hello')   |
+----------------------+
| -7685981735718036227 |
+----------------------+

mysql> select xxhash_64("hello", "world");
+-----------------------------+
| xxhash_64('hello', 'world') |
+-----------------------------+
|         7001965798170371843 |
+-----------------------------+
```

### benchmark

Through TPCH Benchmark testing, it was found that `xxhash_64` has significantly improved performance compared to `murmur_hash3_64`. Therefore, in scenarios where hash values need to be calculated, it is more recommended to use `xxhash_64`.

```
mysql> select count(murmur_hash3_64(l_comment)) from lineitem;
+-----------------------------------+
| count(murmur_hash3_64(l_comment)) |
+-----------------------------------+
|                         600037902 |
+-----------------------------------+
1 row in set (17.18 sec)

mysql> select count(xxhash_64(l_comment)) from lineitem;
+-----------------------------+
| count(xxhash_64(l_comment)) |
+-----------------------------+
|                   600037902 |
+-----------------------------+
1 row in set (8.41 sec)
```

### keywords

XXHASH_64,HASH