ALTER TABLE `table_name` ADD PRIMARY KEY ( `column` )
ALTER TABLE `table_name` ADD UNIQUE ( `column` )
ALTER TABLE `table_name` ADD INDEX index_name ( `column` )
ALTER TABLE `table_name` ADD FULLTEXT ( `column`)
ALTER TABLE `table_name` ADD INDEX index_name ( `column1`, `column2`, `column3` )
SHOW INDEX FROM `table_name`