Our group has a multi-site drupal-D7 installation -- approximately 70 sites -- we need to identify which site have an RSS view. I've been trying to find a signature in the databases' that we could search for to identify which ones have one or more. So far we've been unsuccessful. Is there a way, perhaps a drush command?
You can run the follow SQL command on the databases of the sites:
SELECT * FROM `views_display` WHERE `display_plugin` = 'feed'
Maybe you can use a script to loop through all the databases and get those with results