Mongo-DB is a document database which provides high performance, high availability and easy scalability.
By default, MongoDB created the _id collection for every collection.
No. MongoDB does not support such relationships.
- Flexible data model in form of documents
- Agile and highly scalable database
- Faster than traditional databases
- Expressive query language
Indexes support the efficient execution of queries in MongoDB. Without indexes, MongoDB must perform a collection scan, i.e. scan every document in a collection, to select those documents that match the query statement. If an appropriate index exists for a query, MongoDB can use the index to limit the number of documents it must inspect.
MongoDB uses a database profiler to perform characteristics of each operation against the database. You can use a profiler to find queries and write operations
Yes, it be. Remove the attribute and then re-save () the object.
No. MongoDB can be run on small free space of RAM.
MongoDB stores BSON (Binary Interchange and Structure Object Notation) objects in the collection. The concatenation of the collection name and database name is called a namespace
Q. Mention the command to insert a document in a database called school and collection called persons?
use school;
db.persons.insert( { name: "Pradeep", dept: "CSE" } )It is a group of mongo instances that maintain same data set. Replica sets provide redundancy and high availability, and are the basis for all production deployments.
You should consider embedding documents for:
- contains relationships between entities
- One-to-many relationships
- Performance reasons
Data in MongoDB is stored in BSON documents – JSON-style data structures. Documents contain one or more fields, and each field contains a value of a specific data type, including arrays, binary data and sub-documents. Documents that tend to share a similar structure are organized as collections.
It may be helpful to think of documents as analogous to rows in a relational database, fields as similar to columns, and collections as similar to tables.
Replication is the process of synchronizing data across multiple servers. Replication provides redundancy and increases data availability. With multiple copies of data on different database servers, replication protects a database from the loss of a single server. Replication also allows you to recover from hardware failure and service interruptions.
- The MongoDB store the data in documents with JSON format but SQL store the data in Table format.
- The MongoDB provides high performance, high availability, easy scalability etc. rather than SQL Server.
- In the MongoDB, we can change the structure simply by adding, removing column from the existing documents.
SQL databases store data in form of tables, rows, columns and records. This data is stored in a pre-defined data model which is not very much flexible for today's real-world highly growing applications. MongoDB in contrast uses a flexible structure which can be easily modified and extended.
Yes. An array field can be indexed in MongoDB. In this case, MongoDB would index each value of the array.