Filename Argument Expansion in Zsh

cp dumped_obj_long_filename dumped_obj_long_filename.bkup

Can be shortened to:

cp dumped_obj_long_filename{,.bkup}

To replace a part of the original filename:

cp dumped_obj_long_filename.sql dumped_obj_long_filename.bkup

cp dumped_obj_long_filename.{sql,bkup}