Set Javascript and CSS aggregation with Drush

You can very quickly set Javascript and CSS aggregation on a Drupal site with Drush. The settings are stored as a Drupal variable, so you use the drush vset (vset is an alias for variable-set) command.

The name of the variable for Javacript aggregation is preprocess_js.
The name of the variable for CSS aggregation is preprocess_css.

Enable CSS and Javascript aggregration
drush vset preprocess_css 1
drush vset preprocess_js 1

Disable CSS and Javascript aggregration
drush vset preprocess_css 0
drush vset preprocess_js 0