Estimating MySQL Dump Size before actual export

Estimating the MySQL Dump size before actual export.,

As far as searched through its not possible in MySQL

Here is the comparision between MySQL 6 and ORACLE.
http://blogs.mysql.com/peterg/category/mysql-60-new-features/

Will explore more, if any other tools are available.

However, one quick way might be something like,
checking the size in phpmyadmin or something like that, the rows and overhead by each tables,
then applying some ratios or compression factors to calculate the rough dump size,
It might be something useful.

Will try on this more.

However ORACLE > 10 has ESTIMATE_ONLY