Agregado el 20 de abril de 2015:Lea también Respuesta de Hallie debajo
Primero pero marginalmente. Principalmente porque no tiene que hacer un > 0 extra comparación.
mysql> SELECT BENCHMARK(100000000,LOCATE('foo','foobar'));
+---------------------------------------------+
| BENCHMARK(100000000,LOCATE('foo','foobar')) |
+---------------------------------------------+
| 0 |
+---------------------------------------------+
1 row in set (3.24 sec)
mysql> SELECT BENCHMARK(100000000,LOCATE('foo','foobar') > 0);
+-------------------------------------------------+
| BENCHMARK(100000000,LOCATE('foo','foobar') > 0) |
+-------------------------------------------------+
| 0 |
+-------------------------------------------------+
1 row in set (4.63 sec)
mysql> SELECT BENCHMARK(100000000,'foobar' LIKE '%foo%');
+--------------------------------------------+
| BENCHMARK(100000000,'foobar' LIKE '%foo%') |
+--------------------------------------------+
| 0 |
+--------------------------------------------+
1 row in set (4.28 sec)
mysql> SELECT @@version;
+----------------------+
| @@version |
+----------------------+
| 5.1.36-community-log |
+----------------------+
1 row in set (0.01 sec)
