Data::Dumper tracks "seen" references, and this takes a lot of memory for big structures.

Maybe this helps:

$Data::Dumper::Maxdepth or $OBJ->Maxdepth([NEWVAL])

Can be set to a positive integer that specifies the depth beyond which which we don't venture into a structure. Has no effect when "Data::Dumper::Purity" is set. (Useful in debugger when we often don't want to see more than enough). Default is 0, which means there is no maximum depth.