MongoDB

gistfile1.txt

// Remove N documents from collection
var idsToRemove = db.collection.find({ "query": "to perform" }).limit(10000).sort({ "_id": -1 }).toArray().map(function(doc) { return doc._id;  });
db.collection.remove({ "_id": { $in: idsToRemove }})

// Update
db.collection.update({ "_id": { $set: { "test": "update" } } });

// Get current operations
db.currentOp();

// Count shortcurt
db.collection.count({ "name": "woop" });

// Sort by natural order
db.collection.find({}).limit(10).sort({ $natural: -1 });