lock-tables.md

Lock tables - Example

Example

mysql> LOCK TABLES people write,people_data write;
Query OK, 0 rows affected (0.00 sec)

mysql> UNLOCK TABLES
    -> ;
Query OK, 0 rows affected (0.00 sec)


# LOCK TABLES .... WRITE 
-- We cannot read + write in other session  

# LOCK TABLES ..... READ 
-- We cannot write, but read in other session 

Exercise

Vorbereitung:

• 2 Session die als root mit mysql - client am Server eingeloggt sind

Step 1: Session 1

use sakila;
LOCK TABLES actor write;

Step 2: Session 2

use sakila;
update actor set last_name = 'CHAMPION' where actor_id = 200;
----

Step 3: Session 1

UNLOCK TABLES
-- now update in Step2 should work