koha-dump should provide a way to exclude any database table from the backup process, like --ignore-table switch does in mysqldump command. For example: biblioimages and patronimage tables in most cases are heavy tables that consume a long backup execution time so it would be nice to be able not to do a backup of them. Ref: http://dev.mysql.com/doc/refman/5.1/en/mysqldump.html#option_mysqldump_ignore-table
*** This bug has been marked as a duplicate of bug 12374 ***