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Introduction to MongoDB



MongoDB is a No-SQL database. There are several types of No-SQL databases. Specifically MongoDB is a document database. All data/records are stored as documents. The data is stored using JSON (JavaScript object notation) like syntax.

No-SQL databases are much different from relational databases like MYSQL where all the relations are being mapped,figuring out the exact schema including what table, fields, data type of fields is used  etc..

But in No-SQL the structure of the database/collection is planned but no need to predefined the structure before building the application.




Advantages of MongoDB.

  • High scallability.
                   MongoDB is a horizontally scaled so when there is large amount of data it can be distributed to several machines.
  • Faster. 
                   Since MongoDB is a document oriented database it is easy to access documents by indexing. This provides fast query response. MongoDB is 100 times faster than the relational database.
  • Can deal with big data.
  • High availability.
                   Replication and gridFS help to increase data availability in MongoDB so that the performance is high.
  • Flexible database.
                   Since MongoDB is schema-less we can have any type of data in a separate document.Different types of data can be stored freely and flexibly.
  • Sharding.
                   Large amount of data can be stored by distributing it to several servers connected to the application.
  • Ad-hoc query support.

Disadvantages of MongoDB.

  • Limited data size 
                    Document size note more than 16MB is not allowed.
  • Joins are not supported.
                    MongoDB doe not support joins like the relational database. Joins can be used by coding  it manually.
  • High memory usage.
                    MongoDB stores key names for each value pairs and due to no functionality of joins there is data redundancy resulting unnecessary usage of memory.
  • Limited nesting.
                    Cannot perform nesting of documents for more than 100 levels.

Features of MongoDB.




  • Ad-hoc queries.
  • Schema-less database.
  • Documented oriented.
  • Indexing.
  • Replication.


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