How does the MySQL NULL safe equals operator perform when used with row comparisons?

When we use the NULL-safe operator in row comparison, such as (A, B) 96b4fef55684b9312718d5de63fb7121 (C, D), its performance is equivalent to ( A 96b4fef55684b9312718d5de63fb7121 C) AND (B 96b4fef55684b9312718d5de63fb7121 D). The following example will illustrate −

mysql> Select (100,50) <=> (50,100);
+-----------------------+
| (100,50) <=> (50,100) |
+-----------------------+
|                     0 |
+-----------------------+
1 row in set (0.00 sec)

mysql> Select (100,50) <=> (100,50);
+-----------------------+
| (100,50) <=> (100,50) |
+-----------------------+
|                     1 |
+-----------------------+
1 row in set (0.00 sec)

The above result set shows how to use the NULL safe operator for row comparison.

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