Loop through all Mongo collections and execute query
There is the db.getCollectionNames() helper method that does this for you. You can then implement your code:
db.getCollectionNames().forEach(function(collname) { // find the last item in a collection var last_element = db[collname].find().sort({_id:-1}).limit(1); // check that it's not empty if (last_element.hasNext()) { // print its timestamp printjson(last_element.next()._id.getTimestamp()); }})You probably also want a .hasNext() check in there to cater for possible empty collections.