CP2 Importing ,Exporting,and Querying Data

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How Does MongoDB Store Data?

What is JSON?

JavaScript Object Notation, more commonly known as JSON,was defined as part of the JavaScript language in the early 2000s.

JavaScript objects are simple associative containers, wherein a string key is mapped to a value (which can be a number, string, function, or even another object).

JSON shows up in many different cases:

APIs
Configuration files
Log messages
Database storage

JSON quickly overtook XML, is more difficult for a human to read, significantly more verbose, and less ideally suited to representing object structures used in modern programming languages.

there are several issues that make JSON less than ideal for usage inside of a database.

JSON is a text-based format, and text parsing is very slow
JSON’s readable format is far from space-efficient, another database concern
JSON only supports a limited number of basic data types

In order to make MongoDB JSON-first, but still high-performance and general-purpose, BSON was invented to bridge the gap: a binary representation to store data in JSON format, optimized for speed, space, and flexibility. It’s not dissimilar from other interchange formats like protocol buffers, or thrift, in terms of approach.

What is BSON?

BSON simply stands for “Binary JSON,” and that’s exactly what it was invented to be. BSON’s binary structure encodes type and length information, which allows it to be parsed much more quickly.

Since its initial formulation, BSON has been extended to add some optional non-JSON-native data types, like dates and binary data, without which MongoDB would have been missing some valuable support.

Languages that support any kind of complex mathematics typically have different sized integers (ints vs longs) or various levels of decimal precision (float, double, decimal128, etc.).

Not only is it helpful to be able to represent those distinctions in data stored in MongoDB, it also allows for comparisons and calculations to happen directly on data in ways that simplify consuming application code.

Does MongoDB use BSON, or JSON?

MongoDB stores data in BSON format both internally, and over the network, but that doesn’t mean you can’t think of MongoDB as a JSON database. Anything you can represent in JSON can be natively stored in MongoDB, and retrieved just as easily in JSON.

JSON vs BSON

Schema Flexibility and Data Governance

One of the big attractions for developers using databases with JSON and BSON data models is the dynamic and flexible schema they provide when compared to the rigid, tabular data models used by relational databases.

Firstly, JSON documents are polymorphic – fields can vary from document to document within a single collection

Secondly, there is no need to declare the structure of documents to the database – documents are self-describing. Developers can start writing code and persist objects as they are created.

Thirdly, if a new field needs to be added to a document, it can be created without affecting all other documents in the collection, without updating a central system catalog and without taking the database offline.

Binary JSON, is a binary-encoded serialization of JSON-like documents. Like JSON, BSON supports the embedding of documents and arrays within other documents and arrays. BSON also contains extensions that allow representation of data types that are not part of the JSON spec.

BSON was designed to have the following three characteristics :

1.Lightweight

2.Traversable

3.Efficient