MySQL - Select while sum is less than x -

i've got list of cached files referenced in database , want purge out oldest outside of size limit of 20,000,000.

table simplistically looks this:

[ hash | filesize | timestamp ]

at moment running following command,

select `hash`, `filesize` `cachetable` order `timestamp` desc;

then processing results externally. there way list of results outside of 20,000,000 limit?

i'd use offset

select `hash`, `filesize`  `cachetable`  order `timestamp` desc  limit <your_limit_here>  offset 20000000;

be sure replace your_limit_here own acceptable number.

Camp