Performing DML and DDL Statements on the Underlying InnoDB Table-opracowanie

Performing DML and DDL Statements on the Underlying InnoDB Table
You can access the InnoDB table (by default, test.demo_test) through the standard SQL interfaces.
However, there are some restrictions:
• When query a table through SQL that is also being accessed through the memcached
interface, remember that memcached operations can be configured to be committed
periodically rather than after every write operation. This behavior is controlled by the
daemon_memcached_w_batch_size [1737] option. If this option is set to a value greater than 1,
use READ UNCOMMITTED [1502] queries to find the just-inserted rows:
mysql set session TRANSACTION ISOLATION LEVEL read uncommitted;
Query OK, 0 rows affected (0.00 sec)
mysql select * from demo_test;
+------+------+------+------+-----------+------+------+------+------+------+------+
| cx | cy | c1 | cz | c2 | ca | CB | c3 | cu | c4 | C5 |
+------+------+------+------+-----------+------+------+------+------+------+------+
| NULL | NULL | a11 | NULL | 123456789 | NULL | NULL | 10 | NULL | 3 | NULL |
+------+------+------+------+-----------+------+------+------+------+------+------+
1 row in set (0.00 sec)
• To modify a table through SQL that is also being accessed through the memcached
interface, remember that memcached operations can be configured to be start a new
transaction periodically rather than for every read operation. This behavior is controlled by the
daemon_memcached_r_batch_size [1736] option. If this option is set to a value greater than
1, ...
• The InnoDB table is locked IS (shared intention) or IX (exclusive intentional) for all operations
in a transaction. If you increase daemon_memcached_r_batch_size [1736] and
daemon_memcached_w_batch_size [1737] substantially from their default value of 1, the
table is most likely intentionally locked between each operation, preventing you from running DDL
statements on the table.
... zobacz całą notatkę