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 …