blob's vs varchar

I am wondering about anyones opinion on the best choice for a comment field in a table The comment could be from a sentence to pages and pages long our DBA would like to implement a varchar 256 for short comments and only have a blob for comments over 256 chars eg comment table case_id int comment varchar(256) ( This will hold the first 245 chars of a comment) long_comment table case_id int long_comment text ( This will hold comments longer than 256) The problem with this is i have to pepper my code to check for this condition. and I would have to do an outer join because the long_comment record may or may not be there I would just like to have a blob for all the comments. Any comments ??? thanks :) jk