daniel-sc

// This script loops though all collections of all db in a MongoDB and runs the compact operation on them
// Simply paste this into the Mongo shell

rs.secondaryOk();
db.getMongo().getDBNames().forEach(function(dbName) {
    if ("local" != dbName && "admin" != dbName && "system" != dbName /* use this to (re-)start: && dbName > "am"*/) {
        var subject = db.getSiblingDB(dbName);
        subject.getCollectionNames().forEach(function (collectionName) {
            print(new Date() + ': Compacting: ' + dbName + " - " + collectionName);
            sleep(1000); // assure a cancel (CTRL-C) after "done" is executed before compact command