Sometimes, databases can be quite large. The sql-dump command has a gzip option that will output the SQL dump using the gzip command. In order to run the command, you would simply:
$ drush sql-dump –-gzip dump.sql.gz
The end result provides a reduction in the dump file:
-rw-r--r-- 1 user group 3058522 Jan 14 16:10 dump.sql
-rw-r--r-- 1 user group 285880 Jan 14 16:10 dump.sql.gz
If you create a gzipped database dump, ensure that you unarchive it before attempting an import with the sql-cli command.