MongoDB is written in C document-oriented NoSQL database management system open source, does not require the description of the table schema (schemaless).
MongoDB has the following levels of reporting:
- The document is a JSON object with an arbitrary number of fields. Fields can store both proste value to voennye objects and arrays.
- Collection (table)- the same type documents are stored in separate collections. The documents in the collection can be proindeksirovany. Access dokumentu possible by key and value fields.
- Database - a set of collections.
Support MongoDB is implemented for most programming languages:
- C ;
Differences MongoDB from relational databases:
- Not supported TransAsia. Atomicity is guaranteed only at the level of the whole document, that is, a partial document updates cannot occur. The absence of a mechanism of isolation» qmo. Any data that is read by the same client in parallel, which can be changed by another client.
The benefits of MongoDB relational database before:
- Supports horizontal scaling with replication data. Data can be stored on an arbitrary number of servers. Replication provides fault-tolerance support functions at the output nodes of the system.
- Data storage format (document) is close to the format of data representation in programming languages (objects) does not require complex and expensive queries to get the desired object.
- Support operations for MapReduce massively parallel data processing.
Links to materials for the study
- Getting Started with MongoDB (MongoDB Shell Edition);
- MongoDB QuickStart;
- Guide to MongoDB (memoirs of a thoughtful programmer);
- Security guide MongoDB
- Install MongoDB;
- Official Docker image for MongoDB
- Docker official image of the WEB interface MongoDB
Laboratory work and practical tasks
To install mongoDB the easiest to use docker image with MongoDB.
Start the server by the command:
docker run --name mongodb -p 27017:27017 -d mongo
To work with the mongo server in containere it is recommended to run within the running container mongo-shell command:
docker exec -it mongodb mongo
As practical tasks for laboratory work you can use of the Task for the laboratory work 5 MongoDB. On this page is given as link to the test dataset, and a list of tasks for you to perform operations on these data sets.
Examples of the CRUD and aggregation operations specified in the previous section, data sets, please see pages: