Following node: why does this array take up so much memory? contains some questions about memory usage and received some guidelines from others, including me.

A question about general usage of memory is too generic, try giving us more concrete examples. May be some excerpts from code.

Both memory and speed questions are interesting to solve, and it is widely known that Perl tries to increase speed of running programs and is much less bothering about memory.

Courage, the Cowardly Dog