What is MongoDB
Mongo
DB is one of the most emerging software and is developed by the company
10gen (now MongoDB Inc.) in October 2007 as a component of a planned platform
as a service product, the company shifted to an open source development model
in 2009, with 10gen offering commercial support and other services. MongoDB is
an open source, on the whole a document oriented Database system and is a part
of NoSQL family of database.
10gen definition on MongoDB – “Scalable, open
source, high performance, document oriented database”.
How MongoDB works
MongoDB is a cross-platform document-oriented
database. Classified as a NoSQL database, MongoDB eschews the traditional table-based relational
database structure in favour of JSON-like documents with dynamic schemas (MongoDB calls the format BSON), making the integration of data in certain types of applications
easier and faster. MongoDB works on concept of collections and documents.
MongoDB Features
Document-Oriented Storage
MongoDB can store the business subject in the
minimal number of documents. A document is a set of key-value pairs. Documents
have dynamic schema. Dynamic schema means that the documents in the same
collection do not need to have the same set of fields or structure, and common
fields in a collection's documents may hold different types of data.
Ex1:
{ Ex2: {
id: "1", id: "1",
name: "TEST" name: "TEST",
} address:
{
street: “test street”,
city:”test city” , state: "MA",
zip:
"12345"
}
}
MongoDB provides high availability using
replication facility, called replica sets. 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.
Easy Scalability
Scalability is the ability of a database
system to handle a growing amount of work in a capable manner or its ability to
be enlarged to accommodate that growth.
High Performance
One of the key features of MongoDB is high
performance and It is achieved with its data models and special type of indexing
technique.
MongoDB supports embedded data model; it
reduces the I/O activity on database system. Data in MongoDB for a record is
stored in a single document nested blocks.
So the data retrieving is very efficient and improves the performance.
Advantages of MongoDB over RDBMS
Instead of storing data in tables here rows
are replaced by Documents (basic unit of Data in Mongo DB just like a ROW in
RDMS) and Collections (collection is a group of documents.) which allow
representing complex relationships. It can manage huge amount of data and can
load data across a cluster. Mongo DB can perform some features which relational
database cannot do.
o Schema less:
MongoDB is document database in which one collection holds different documents.
Number of fields, content and size of the document can be differ from one
document to another.
o Structure of a
single object is clear
o No complex joins: It removes the need for
complex transactions or joins due to the advantages of having data for a record
contained within a single document
o Deep query
ability
o MongoDB
supports dynamic queries on documents using a document based query language
that's nearly as powerful as SQL
o Performance
tuning is done with mongodb
o Ease of scale
out: MongoDB is easy to scale
o Ease of Use
(Developer Friendly)
o Mongodb is an
open source software
o Java Scripts
are used instead of long Procedures
o MongoDB stores
files of any size without complicating your stack.
o Most
Importantly Mongo DB supports secondary indexes and geospatial indexes.
o Mongo DB supports
Map reduce and Aggregation Tools
o Conversion/mapping
of application objects to database objects not needed
o Simple to
Administer the Mongo DB in cases of failures
Compare MongoDB to RDBMS
o RDBMS is high
functional than MongoDB
Limitations of MongoDB
o No Joins
support
o No complex
transactions support
o No constraints
support database level
o Consumption of
disk space is more
o Indexes take
up lot of RAM
o 12-node limit
to the replica-set strategy
o No support for
transactions
o Manual changes
to master node in the master-slave strategy
o 32-bit MongoDB
only handles 2GB of data
