l2_norm()

函数说明

l2_norm 函数用于计算 l2/欧几里得范数。l2 范数通过对向量元素的平方和进行平方根运算得到。

函数语法

> SELECT l2_norm(vector) AS result FROM table_name;

示例

drop table if exists vec_table;
create table vec_table(a int, b vecf32(3), c vecf64(3));
insert into vec_table values(1, "[1,2,3]", "[4,5,6]");
mysql> select * from vec_table;
+------+-----------+-----------+
| a    | b         | c         |
+------+-----------+-----------+
|    1 | [1, 2, 3] | [4, 5, 6] |
+------+-----------+-----------+
1 row in set (0.00 sec)
mysql> select l2_norm(b) from vec_table;
+--------------------+
| l2_norm(b)         |
+--------------------+
| 3.7416573867739413 |
+--------------------+
1 row in set (0.01 sec)