Where can we use ElasticSearch and Where can we use MongoDB?

Question

我的问题是，在哪种情况下我们可以选择MongoDB，在哪种情况下我们可以选择ElasticSearch。

Answer 1

If you have a case where you want to do search on particular word and you know that word is present in your db you can go for mongodb directly. But if you have a case where you want to do search partially then go for elastic search.

Example: If you do text indexing on your document's some fields, mongo text search will work on single word search. Suppose you have test field in your collection you did text indexing. test field has value " I am testing it ". on text search if you pass "testing" it will give you the document which has "testing" word in collection. But now if you search for "test" you will gonna get no data. Instead if you try doing the same in elastic search even for "tes","testi" etc. partial search you will gonna get data in response.

reference: http://blog.mpayetta.com/elasticsearch/mongodb/2016/08/04/full-text-indexing-with-elastic-search-and-mongodb/