MySQL error: key specification without a key length

Question

I have a table with a primary key that is a varchar(255). Some cases have arisen where 255 characters isn\'t enough. I tried changing the field to a text, but I get the foll

Answer 1

Don't have long values as primary key. That will destroy your performance. See the mysql manual, section 13.6.13 'InnoDB Performance Tuning and Troubleshooting'.

Instead, have a surrogate int key as primary (with auto_increment), and your loong key as a secondary UNIQUE.