LOAD DATA FROM MASTER (removed)
Syntax
LOAD DATA FROM MASTER
Description
This feature has been removed from recent versions of MariaDB.
Since the current implementation of LOAD DATA FROM MASTER
and LOAD TABLE FROM MASTER is very limited, these statements are deprecated in versions 4.1 of MySQL and above. We will introduce a more
advanced technique (called "online backup") in a future version. That technique
will have the additional advantage of working with more storage engines.
For MySQL 5.1 and earlier, the recommended alternative solution to
using LOAD DATA FROM MASTER or
LOAD TABLE FROM MASTER is using mysqldump or mysqlhotcopy.
The latter requires Perl and two Perl modules (DBI and DBD:mysql) and works for
MyISAM and ARCHIVE tables only. With mysqldump, you can create SQL dumps on the
master and pipe (or copy) these to a mysql client on the slave. This has the
advantage of working for all storage engines, but can be quite slow, since it
works using SELECT.
This statement takes a snapshot of the master and copies it to the slave. It
updates the values of MASTER_LOG_FILE and
MASTER_LOG_POS so that the slave starts replicating from
the correct position. Any table and database exclusion rules specified with the
--replicate-*-do-* and
--replicate-*-ignore-* options are honored.
--replicate-rewrite-db is not taken into account because a
user could use this option to set up a non-unique mapping such as
--replicate-rewrite-db="db1->db3" and
--replicate-rewrite-db="db2->db3", which would confuse the
slave when loading tables from the master.
Use of this statement is subject to the following conditions:
- It works only for MyISAM tables. Attempting to load a non-MyISAM table
results in the following error:
ERROR 1189 (08S01): Net error reading from master - It acquires a global read lock on the master while taking the snapshot, which prevents updates on the master during the load operation.
If you are loading large tables, you might have to increase the values of
net_read_timeout and net_write_timeout on
both the master and slave servers.
See Server System Variables.
Note that LOAD DATA FROM MASTER does not copy any tables
from the mysql database. This makes it easy to have different users and
privileges on the master and the slave.
To use LOAD DATA FROM MASTER, the replication account that
is used to connect to the master must have the RELOAD and
SUPER privileges on the master and the
SELECT privilege for all master tables you want to load.
All master tables for which the user does not have the
SELECT privilege are ignored by
LOAD DATA FROM MASTER. This is because the master hides
them from the user: LOAD DATA FROM MASTER calls
SHOW DATABASES to know the master databases to load, but
SHOW DATABASES returns only databases
for which the user has some privilege. On the slave side, the user that
issues LOAD DATA FROM MASTER must have privileges for
dropping and creating the databases and tables that are copied.
