Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{"name":"ahmet"},{"name":"barış"},{"name":"ceyhun"},{"name":"aslan"},{"name":"deniz"}]
Query
db.collection.aggregate([{$match:{name:{$regex:"^a|^b|^c"}}},{"$sample":{"size":3}}])
Result