In the first version, the remote server must be a MySQL
server. Support by FEDERATED for other
database engines may be added in the future.
The remote table that a FEDERATED table
points to must exist before you try to
access the table through the FEDERATED
table.
It is possible for one FEDERATED table to
point to another, but you must be careful not to create a
loop.
There is no support for transactions.
There is no way for the FEDERATED engine
to know if the remote table has changed. The reason for this
is that this table must work like a data file that would
never be written to by anything other than the database. The
integrity of the data in the local table could be breached
if there was any change to the remote database.
The FEDERATED storage engine supports
SELECT, INSERT,
UPDATE, DELETE, and
indexes. It does not support ALTER TABLE,
DROP TABLE, or any other Data Definition
Language statements. The current implementation does not use
Prepared statements.
The implementation uses SELECT,
INSERT, UPDATE, and
DELETE, but not
HANDLER.
FEDERATED tables do not work with the
query cache.
