Mysql Partitioning of Attachments table

Hey folks,
I’m running RT4.2 mysql 5.5 with file_per_table; my Attachments table has
grown quite large and it’s becoming a nuisance to maintain it. I think the
right solution is to partition to table into multiple files.

Since the table is write once read many it makes sense to me to partition
based on current partition file size (ie when this partition file of the
Attachments table greater than say 100MB create a new partition file and
use that as current). This way table optimize will only happen on the
newest partition(s) as the old ones will be optimized one last time (after
the final write that exceeds the file size threshold) and then will remain
a static file.

Unfortunately it seems that mysql does not support partitioning that way so
my next best option is probably to partition by id or Created and assign
ranges but I would rather do future partitioning automatically.

Any suggestions welcomed.

thanks
ram