Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{name:"A"},{name:"A1"},{name:"B"},{name:"B1"},{name:"C"},{name:"C1"}]
Query
db.collection.find({$or:[{name:{$regex:"A",}},{name:{$regex:"B",}}]})
Result