What is difference between createIndex and ensureIndex in MongoDB?

What is difference between createIndex and ensureIndex in MongoDB?

I believe the original intent of the methods was that “createIndex” returns a status if the index already exists, while “ensureIndex” does not. There is no “ensureIndex” command on the server side, so the mongo shell and drivers are actually providing the “ensure” logic.

What is ensureIndex in MongoDB?

They store the value of a specific field or more than one fields (i.e. set of fields), which are ordered by the value of the field as indicated in the index. The ensureIndex () Method. In MongoDB, we use ‘ensureIndex ()’ method to create an index.

Which of the following is correct syntax of createIndex?

3. Which of the following is correct CREATE INDEX Command? Explanation: The basic syntax of a CREATE INDEX is as follows : CREATE INDEX index_name ON table_name; 4.

How do I create an index in Nosql?

MongoDB provides a method called createIndex() that allows user to create an index. The key determines the field on the basis of which you want to create an index and 1 (or -1) determines the order in which these indexes will be arranged(ascending or descending).

Which of the following method is used to create index in MongoDB?

createIndex”
Creating an Index in MongoDB is done by using the “createIndex” method.

What is the type of weights parameter in createIndex ()?

Explanation: The type of weights parameter in createIndex() is document.

In which directory does MongoDB write data by default?

/data/db directory
Create the data directory¶ Before you start MongoDB for the first time, create the directory to which the mongod process will write data. By default, the mongod process uses the /data/db directory.

What is DB in MongoDB command?

MongoDB use DATABASE_NAME is used to create database. The command will create a new database if it doesn’t exist, otherwise it will return the existing database.

Which method is used to create an index?

createIndex method
Indexes can be created by using the createIndex method.

Can we create index in MongoDB?

Collation and Index Use If you do not specify a collation when creating the index, MongoDB creates the index with the collection’s default collation. If you do specify a collation when creating the index, MongoDB creates the index with the specified collation.

How do I create a compound index in MongoDB compass?

To create an index on a collection via Compass, the collection must contain documents.

1. Click the Create Index button. From the Indexes tab, click the Create Index button to bring up the Create Index dialog.
2. Optional. Enter the index name.
3. Add fields to index. Specify an index key.