I have table
owner_id INT, value VARCHAR(255), type INT
CREATE TABLE field_contents(field_id INT, content TEXT)
I don't see anything wrong with adding the
content column to the original
fields table, at least from a storage point of view.
NULL values in variable length columns in MySQL do not take up any space in the row themselves. Since
TEXT is a
BLOB type, and has a variable length, the empty entries in your table should therefore not be a performance killer for storage.
As to whether the
content column logically belongs in the
fields table itself depends on your database design.
Read here for more information.