Introduction to Mongodb
- 1. MongoDB
- 2. What is mongoDB MongoDB is a document database with the scalability and flexibility that you want with the querying and indexing that you need 1.MongoDB stores data in flexible, JSON-like documents, meaning fields can vary from document to document and data structure can be changed over time 2.The document model maps to the objects in your application code, making data easy to work with 3.Ad hoc queries, indexing, and real time aggregation provide powerful ways to access and analyze your data
- 3. Why use MongoDB? 1. MongoDB stores documents (or) objects and Now-a-days, everyone works with objects (Python/Ruby/Java/etc.) 2. Scalable High-Performance Open-source, Document-orientated database. 3. Built for Speed & Rich Document based queries for Easy readability. 4. Full Index Support for High Performance. 5. Replication and Failover for High Availability. 6. Auto Sharding for Easy Scalability & Map / Reduce for Aggregation.
- 4. What is MongoDB great for? 1. Semi-structured Content Management. 2. Real-time Analytics & High-Speed Logging. What is MongoDB not great for? 1. Highly Transactional Applications. 2. Problems requiring SQL.
- 5. How mongoDB differs from traditional dbs ? SQL Database Relational database Supports SQL query language Table , Row and Column based Support foreign key and triggers Emphasizes on ACID properties (Atomicity, Consistency, Isolation and Durability) SQL Database Relational database Supports SQL query language Table , Row and Column based Support foreign key and triggers Emphasizes on ACID properties (Atomicity, Consistency, Isolation and Durability)
- 6. Analogy of MongoDB with traditional dbs Database Table Record/row Column Index Join Foreign Key Partition Database Table Record/row Column Index Join Foreign Key Partition
- 7. Query Operators $eq $gt, $gte $lt, $lte $ne $in $nin $or $and $not $nor $exists $eq $gt, $gte $lt, $lte $ne $in $nin $or $and $not $nor $exists
- 8. MongoDB: CAP approach Consistency 1. all replicas contain the same version of the data Availability 1. system remains operational on failing nodes Partition tolarence 1. multiple entry points 2. system remains operational on system split
- 9. BSON format Binary-encoded serialization of JSON-like documents 1.Zero or more key/value pairs are stored as a single entity 2. Each entry consists of a field name, a data type, and a value 3. Large elements in a BSON document are prefixed with a length field to facilitate scanning
- 10. Work with mongo mongod 1. mongod is the primary daemon process for the MongoDB system. It handles data requests, manages data access, and performs background management operations. Mongos 1. mongos for MongoDB Shard, is a routing service for MongoDB shard configurations that processes queries from the application layer, and determines the location of this data in the sharded cluster
- 11. Crud in MongoDB show dbs; (will list out the database that present in the mongodb) use exampledb; (will switch or create new database) Db.CreateCollection(); Db.collectionName.Insert({key:value}); Db..collectionName.remove({key:value}) db.inventory.find( { id: value" } ) db.dropDatabase();
- 12. Map Reduce Functionality Map (Key , Value) -> Reduce ()-> Final Output
- 14. Sharding in mongo Sharding It is a method for distributing data across multiple machines. MongoDB uses sharding to support deployments with very large data sets and high throughput operations. Scaling 1.Vertical Scaling 2.Horizontal Scaling
- 15. Sharded Cluster A MongoDB sharded cluster consists of the following components: Shard : Each shard contains a subset of the sharded data. Each shard can be deployed as a replica set. Mongos: The mongos acts as a query router, providing an interface between client applications and the sharded cluster. config servers : Config servers store metadata and configuration settings for the cluster. As of MongoDB 3.4, config servers must be deployed as a replica set (CSRS).
- 16. Chunks : MongoDB partitions sharded data into chunks. Each chunk has an inclusive lower and exclusive upper range based on the shard key Shard Keys : To distribute the documents in a collection.
- 17. references 1. http://docs.mongodb.org/manual/tutorial/getting-started/ 2. https://www.tutorialspoint.com/mongodb/mongodb_overview.htm 3. http://www.c-sharpcorner.com/article/overview-of-mongodb/