To my understanding both Elasticsearch and MongoDB are capable of doing inverted indexing of the stored data and allow full text search. Both Elasticsearch and MongoDB store JSON documents in database Reference
What I dont understand is what is special about indexing that Elasticsearch can do which MongoDB cant do? Elasticsearch also has size limit of 100 MB whereas MongoDB can store large files using GridFS API?
I went through some the references mentioned and dont understand what is so special about Elasticsearch compared to other document-based database that also perform advanced indexing so dont understand why Elasticsearch is even used if it cannot handle bigdata > 4GB which other database can handle.
