How do I add a MySQL Index Key to Improve Select Performance?

If you have a MySQL database, you can improve performance by adding index keys.

Indexing makes it so that SELECT statements will execute faster, when you have a WHERE clause that uses an indexed key. The speed different can be insignificant (on small DB's), or tremendous (on bigger DB's).

Add a MYSQL index to a column like this....

MyDB@sys mysql> ALTER TABLE `MyTable` ADD INDEX `MyColumn` (`MyColumn`);

Then you will get better performance with statements like...

MyDB@sys mysql> SELECT * FROM MyTable WHERE MyColumn = 'SomethingIWant';

You can also verify the keys a table has with....

MyDB@sys mysql> SHOW KEYS FROM MyTable;

Or, even with this....

MyDB@sys mysql> SHOW CREATE TABLE MyTable;