The first introduction of the most complete mongodb in history

MongoDB List of articles

• In the history of the most complete MongoDB First knowledge of

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Preface

This series of courses will take you in the form of face-to-face test questions Go deep into distributed topics MongoDB. This article takes you to know for the first time MongoDB

What is? MongoDB

• MongoDB It's based on Distributed file storage The database of . from C++ Language writing .
• The supporting data structure is very loose , The data format is BSON
• Support dynamic query
• Support for replication and recovery
• Support Golang,RUBY,PYTHON,JAVA,C++,PHP,C# multilingual

BSON（binary json） And JSON The difference between

• Binary JSON , and JSON It also supports embedded document objects and array objects , Therefore, more complex data types can be stored
• BSON Faster traversal speed
• BSON It's easier to operate
• BSON Added additional data types

MongoDB Version history

• 2012 year 05 month 23 Japan ,MongoDB2.1 The development branch has released ! This version uses a new architecture , There are many enhancements .
• 2012 year 06 month 06 Japan ,MongoDB 2.0.6 Release , Distributed document database .
• 2013 year 04 month 23 Japan ,MongoDB 2.4.3 Release , This release includes some performance optimizations , Enhancements and bug Repair .
• 2013 year 08 month 20 Japan ,MongoDB 2.4.6 Release .
• 2013 year 11 month 01 Japan ,MongoDB 2.4.8 Release .
• 2017 year 03 month 17 Japan ,MongoDB 3.0.1 Release .
• 2018 year 08 month 06 Japan ,MongoDB 4.0.2 Release , Support multiple document transactions .
• 2019 year 08 month 13 Japan ,MongoDB 4.2.0 Release , Introduce distributed transactions .

MongoDB With relational databases (RDBMS) contrast

Common ground

Relational database (RDBMS)	MongoDB
database (database)	database (database)
surface (table)	aggregate (collection)
That's ok (row)	file (document)
Column (column)	Field (field)
Indexes (index)	Indexes (index)
Primary key (primary key)	_id( Field )
View (view)	View (view)
Table links (table join)	Aggregation operation ($lookup)

Difference

• MongoDB have Semi structured characteristic . No field declaration is required , And the fields in the set do not need to be exactly the same
• MongoDB No foreign key constraints , Table connection requires the use of aggregate Pipeline Technology ($lookup) Realization

MongoDB Explanation of the name

Noun	explain
database （database）	It can be understood as a logical namespace , A database contains multiple collections with different names
aggregate （collection）	amount to * Relational database (RDBMS)* In the table
file （document）	A document is equivalent to a row in a data table , It consists of several different fields
Field （field）	An attribute in the document , Equate to Relational database (RDBMS) Of Column （column）
Indexes （index）	Independent retrieval data structure , And SQL Consistent concept
_id	Each document has a unique id Field
View （view）	Virtual （ It's not real ） aggregate , And SQL The view in is similar to , It is realized through polymerization pipeline technology
Aggregation operation （$lookup）	Used to implement " similar " Table joins （tablejoin） The aggregation operator for

MongoDB Advantages over other databases

• Document storage
  MongoDB use BSON/JSON Documents store data
• High scalability and high availability
  MongoDB Support data fragmentation , Replication sets provide 99.999% High availability
• Easy to query
  JSON The structure is close to the object model , Low amount of development code
• High safety
  MongoDB The query generated by the client is BSON object , To reduce the SQL Danger of injected attack