Dear busunl ,
Do you meant to say that each perl program will consume their required memory when it starts ?
One more question is whether it acquires more memory during run time

It does not acquire all memory when it starts.

It will get more memory during runtime when needed.

There are two major points in perl memory management:

1. You don't have to bother, perl will do that for you
2. Memory will not be freed during runtime

That's all.