I have an application in production now (actually a DNS server) which answers in excess of 100 queries/sec, uses DBI to talk to its backend (DBD::Oracle) and its footprint is nowhere near that.

I think you definitely have a memory leak. Please observe the pattern of memory usage. If it grows slowly, a leak is the most likely cause.

As others said, if you post your code (or the relevant parts of it), probably a lot of help can result :)

Good luck.