db.transactions.find({"_id":{"$gt":ObjectId("16a4f6b7d1adb1796ce2e091")},"userId": {$regex:'89A105e1',$options: 'i'}}) * ^ $
db.transactions.find({"_id":{"$gt":ObjectId("16a4f6b7d1adb1796ce2e091")},"type": {$regex:'^RE'}})
db.users.find({name: /a/})
{ sku: { $regex: /^ABC/i } }
db.tweets.find( {_id : { "$lt" : <50th _id> } } ).limit(50).sort({"_id":-1});
db.tweets.find( {_id : { "$gt" : <50th _id> } } ).limit(50).sort({"_id":1});
db.transactions.find({"_id":{"$gt":ObjectId("16a4f6b7d1adb1796ce2e091")},"storeId":/^003/i})
db.test.find({amount:{$gt:2399927}}).sort({"amount":1}).limit(10)
sort({"_id":-1}).l
find({'_id'> last_id}). sort().limit(10)
collection.aggregate({$unwind: u}, {$group: g},{$match: f}, {$sort: s}, {$limit: l}, {$skip: p})