MongoDB large collection and slow search? How to fix?

For faster search, create index. For this, use createIndex(). Let us create a collection with documents −

> db.demo661.createIndex({ListOfName:1});
{
   "createdCollectionAutomatically" : true,
   "numIndexesBefore" : 1,
   "numIndexesAfter" : 2,
   "ok" : 1
}
> db.demo661.insertOne({_id:1,ListOfName:["John","Robert","David"]});
{ "acknowledged" : true, "insertedId" : 1 }
> db.demo661.insertOne({_id:2,ListOfName:["Mike","Sam"]});
{ "acknowledged" : true, "insertedId" : 2 }
> db.demo661.insertOne({_id:3,ListOfName:["John","David","Bob"]});
{ "acknowledged" : true, "insertedId" : 3 }

Display all documents from a collection with the help of find() method −

> db.demo661.find();

This will produce the following output −

{ "_id" : 1, "ListOfName" : [ "John", "Robert", "David" ] }
{ "_id" : 2, "ListOfName" : [ "Mike", "Sam" ] }
{ "_id" : 3, "ListOfName" : [ "John", "David", "Bob" ] }

Following is the query to fetch documents −

> db.demo661.find({"ListOfName": {"$all":["John","David"]}});

This will produce the following output −

{ "_id" : 1, "ListOfName" : [ "John", "Robert", "David" ] }
{ "_id" : 3, "ListOfName" : [ "John", "David", "Bob" ] }

AmitDiwan

Published on 13-May-2020 09:29:11

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