What Happens to MEMORY Tables When MySQL Server Is Stopped? - MySQL FAQs - Storage Engines: MyISAM, InnoDB and BDB

If you have data rows stored in a table with the MEMORY storage engine, and the MySQL server has been shutdown by the DBA, all data rows will be removed. But the table structure will remain in the server.

The tutorial exercise below shows you a good example of using MEMORY tables:

>cd \mysql\bin\mysql -u dev -piyf fyi

mysql> INSERT INTO fyi_memory (id) VALUES (-1);
Query OK, 1 row affected (0.00 sec)

mysql> INSERT INTO fyi_memory (id, count) VALUES (-2, 987);
Query OK, 1 row affected (0.01 sec)

mysql> SELECT * FROM fyi_memory;
+----+-------+-------+
| id | title | count |
+----+-------+-------+
| -1 | NULL  |  NULL |
| -2 | NULL  |   987 |
+----+-------+-------+
2 rows in set (0.00 sec)

mysql> quit;

>\mysql\bin\mysqladmin -u root -pretneciyf shutdown

>\mysql\bin\mysqld-max

>\mysql\bin\mysql -u dev -piyf fyi

mysql> SELECT * FROM fyi_memory;
Empty set (0.00 sec)