Mysql, PHP, contatori, lock table & locks in generale

[brancomat]

Ho provato, ma non riesco a cambiare il livello di isolamente (nota: sto usando l'utente ROOT)

MariaDB [konsorzio]> select @@autocommit;
+--------------+
| @@autocommit |
+--------------+
|            1 |
+--------------+
1 row in set (0.00 sec)

MariaDB [konsorzio]> SELECT @@GLOBAL.tx_isolation, @@tx_isolation;
+-----------------------+-----------------+
| @@GLOBAL.tx_isolation | @@tx_isolation  |
+-----------------------+-----------------+
| REPEATABLE-READ       | REPEATABLE-READ |
+-----------------------+-----------------+
1 row in set (0.00 sec)

MariaDB [konsorzio]> set transaction isolation level serializable;
Query OK, 0 rows affected (0.00 sec)

MariaDB [konsorzio]> SELECT @@GLOBAL.tx_isolation, @@tx_isolation;
+-----------------------+-----------------+
| @@GLOBAL.tx_isolation | @@tx_isolation  |
+-----------------------+-----------------+
| REPEATABLE-READ       | REPEATABLE-READ |
+-----------------------+-----------------+
1 row in set (0.00 sec)
Qui provo a impostare i parametri ma... non cambiano!

MariaDB [konsorzio]> set autocommit=0;
Query OK, 0 rows affected (0.00 sec)

MariaDB [konsorzio]> set transaction isolation level serializable;
Query OK, 0 rows affected (0.00 sec)

MariaDB [konsorzio]> SELECT @@GLOBAL.tx_isolation, @@tx_isolation;
+-----------------------+-----------------+
| @@GLOBAL.tx_isolation | @@tx_isolation  |
+-----------------------+-----------------+
| REPEATABLE-READ       | REPEATABLE-READ |
+-----------------------+-----------------+
1 row in set (0.00 sec)

MariaDB [konsorzio]>