Question

i have a chat system using Storage Engine [Memory] but varchar 255 is way too short, what field type should i use? I dont plan on indexing this field.

Answer 1

You can’t use blob or text in a memory table, but you may be able to use a longer varchar depending on your version of MySQL:

Values in VARCHAR columns are
variable-length strings. The length
can be specified as a value from 0 to
255 before MySQL 5.0.3, and 0 to
65,535 in 5.0.3 and later versions.
The effective maximum length of a
VARCHAR in MySQL 5.0.3 and later is
subject to the maximum row size
(65,535 bytes, which is shared among
all columns) and the character set
used.

http://dev.mysql.com/doc/refman/5.0/en/char.html