Mysql MediumText causes PHP Fatal error: Allowed memory size of 8388608 bytes exhausted -

I have my own php data object class that wraps MySQLite library. Most of the data including this text works properly. As soon as I change the table column from text to medium text, I get the error described in the title of this question. I have tested my PHP scripts on many shared hosting environments, and I get this error on one of these.

Does Medium Text and Long Text Really Use That Memory?

I will start customizing my php classes, but I want to make sure that I am on the right track ..

May be as 16777215 as specified in the medium text

This will be defined as PHP in terms of memory limit. So it makes sense