Something

RENAME TABLE customers_fact_log TO customers_fact_log_1;
CREATE TABLE customers_fact_log_2 LIKE customers_fact_log_1;
CREATE TABLE customers_fact_log (
    `customers_fact_log_id` int(11) NOT NULL auto_increment,
    `customers_id` int(11) NOT NULL default '0',
    `fact_type_id` int(11) NOT NULL default '0',
    `date` datetime NOT NULL default '0000-00-00 00:00:00',
    `attr1` varchar(255) default NULL,
    `attr2` varchar(255) default NULL,
    `attr3` varchar(255) default NULL,
    `attr4` varchar(255) default NULL,
    `attr5` varchar(255) default NULL,
    `attr6` varchar(255) default NULL,
    `attr7` varchar(255) default NULL,
    `attr8` varchar(255) default NULL,
    `attr9` varchar(255) default NULL,
    `attr10` varchar(255) default NULL,
    `attr11` varchar(255) default NULL,
    `attr12` varchar(255) default NULL,
    `attr13` varchar(255) default NULL,
    `attr14` varchar(255) default NULL,
    `attr15` varchar(255) default NULL,
    `attr16` varchar(255) default NULL,
    `attr17` varchar(255) default NULL,
    `attr18` varchar(255) default NULL,
    `attr19` varchar(255) default NULL,
    `attr20` varchar(255) default NULL,
    PRIMARY KEY  (`customers_fact_log_id`))
ENGINE=MERGE 
UNION=(customers_fact_log_1, customers_fact_log_2) 
INSERT_METHOD=LAST;