If you need to edit a big file, for example a mysql full dump for recover a single database, and your editor, for example emacs, say
something like "Maximum buffer size exceeded" you can split it in many smaller files.

~$ split -b 100m ORIGINAL_BIG_FILE OUTPUT_FILE_NAME

Output files will be:

OUTPUT_FILE_NAMEaa
OUTPUT_FILE_NAMEab
OUTPUT_FILE_NAMEac

and on ... every one 100MB weight.

Then you can edit and just keep your DB for restore.