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)