If you get error when dumping DB with drush CLI that says something like this
mysqldump: Error 2020: Got packet bigger than 'max_allowed_packet' bytes when dumping table `simple_sitemap` at row: 0 [error] Database dump failed [error] Unable to drop database. Rerun with --debug to see any error message.
then you obviously need to change "max_allowed_packet", you can do that also with drush, logging in to mysql with command
and then check max_allowed_packet value with SHOW VARIABLES LIKE 'max_allowed_packet'; when you get some value, it will be in bytes, so google it how to know value in MB or just calculate it yourself. Raise the value to some new one, for example
128 Megabytes = 134217728 Bytes
64 Megabytes = 67108864 Bytes
32 Megabytes = 33553408 Bytes
to do that, run SET GLOBAL max_allowed_packet=134217728; in CLI. Quit drush sqlc and run it again, check the value as before, it should be now changed to new value.