TEXT fields are a nightmare. For you and for your server. It is slow to retrieve, and if you are doing searches on it, be prepared, things are going to get bumpy.

If you use MySQL with a MyISAM engine, this may not be an issue for you, you can create a FULLTEXT index, your only problem is if you want to add a new column, an alter table can take forever, since MySQL creates a new table and copies the old data to the new table. For those who uses MySQL with an InnoDB engine, prepare because, you’ll have more issues. Indexes can’t be FULLTEXT and if you do need an index you must inform the length of it. It defeats the purpose of you doing the search in that field.

The observation above is only true for MySQL 5.5 or below, since version 5.6 MySQL does support FULLTEXT indexes on InnoDB – thanks Davey …