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What does Projection do in MongoDB?
In MongoDB, projection means selecting only the necessary data rather than selecting whole of the data of a document. If a document has 5 fields and you need to show only 3, then select only 3 fields from them.
Why MongoDB has high performance?
Why is MongoDB high performance? Ad hoc queries, indexing, and real time aggregation provide powerful ways to access data. MongoDB is a distributed database by default, which allows for expansive horizontal scalability without any changes to application logic.
Is MongoDB a performance?
MongoDB is faster than MySQL due to its ability to handle large amounts of unstructured data when it comes to speed. It uses slave replication, master replication to process vast amounts of unstructured data and offers the freedom to use multiple data types that are better than the rigidity of MySQL.
Why do we need GridFS in MongoDB?
If your filesystem limits the number of files in a directory, you can use GridFS to store as many files as needed. When you want to access information from portions of large files without having to load whole files into memory, you can use GridFS to recall sections of files without reading the entire file into memory.
Why is MongoDB faster than SQL?
MongoDB uses internal memory for storing working sets resulting in faster access time. MongoDB supports deep query-ability i.e we can perform dynamic queries on documents using the document-based query language that’s nearly as powerful as SQL.
How to optimize query performance in MongoDB?
When you need only a subset of fields from documents, you can achieve better performance by returning only the fields you need: For example, if in your query to the posts collection, you need only the timestamp, title, author, and abstract fields, you would issue the following command:
How do you do projection in MongoDB query?
MongoDB projection is a query where we can specify the fields we would like to have returned. We can do projection in MongoDB by adding a 0 or 1 next to fields name after including in a query. If you specify the parameter 1 it will be displayed and 0 will hide it.
How does the$ Inc operator work in MongoDB?
Use MongoDB’s $inc operator to increment or decrement values in documents. The operator increments the value of the field on the server side, as an alternative to selecting a document, making simple modifications in the client and then writing the entire document to the server.
Why do you need an index in MongoDB?
Indexes also improve efficiency on queries that routinely sort on a given field. If you regularly issue a query that sorts on the timestamp field, then you can optimize the query by creating an index on the timestamp field: Because MongoDB can read indexes in both ascending and descending order, the direction of a single-key index does not matter.