1. Create an index
Index creation can be performed in the CREATE TABLE statement, or CREATE INDEX or ALTER TABLE can be used alone to add an index to a table. The following command statements respectively show how to create a primary key index (PRIMARY KEY), a joint index (UNIQUE) and a common index (INDEX).
mysql>ALTER TABLE `table_name` ADD INDEX|UNIQUE|PRIMARY KEY| `index_name` (column list); mysql>CREATE [UNIQUE] INDEX `index_name` ON `table_name` (column_list);
2. Rebuild the index
Reindexing is often used in routine database maintenance operations. After the database has been running for a long time, the index may be damaged, and then it needs to be rebuilt. Reindexing data can improve retrieval efficiency.
mysql> REPAIR TABLE `table_name` QUICK;
3. Query data table index
mysql> SHOW INDEX FROM|IN `table_name`;
4. Delete the index
Dropping an index can be done using the ALTER TABLE or DROP INDEX statement. DROP INDEX can be handled as a single statement inside ALTER TABLE with the following format:
mysql>DROP index `index_name` ON `table_name` (column list); mysql>ALTER TABLE `table_name` DROP INDEX|UNIQUE|PRIMARY KEY `index_name` (column list);
Article source: http://blog.icodeu.com/?p=645