Build it into hashes and arrays in perl and it will pop up to at least 100mb, get sloppy and copy instead of use refs and you can grow that amount very qucikly and cause big slowdowns. modify in memory and delay writes to disk and you can kiss it goodbye on poweroutage/system crash. Even though it may be possible (or even prudent) to do it in all memory understand the risks and problems you may be up against. If you have oracle/sybase/ms-sql licenses use what you have, else there are free databases such as mysql and postgres.