Introduction to nosql
- 2. Agenda RDBMS & its Limitations ACID v/s BASE CAP Theorem Introduction to NOSQL & its Characteristics Types of NOSQL Databases Choosing the right fit Disadvantages 2
- 3. Since 1970 Use SQL to manipulate data Easy to use Easy to integrate with other system Fits most of our legacy application demands Relational DBMS 3
- 4. What is problem of RDBMS? 4
- 5. BASE Basic Availability: Each request is guaranteed a response—successful or failed execution Soft state: The state of the system may change over time, at times without any input (for eventual consistency) Eventual consistency: The database may be momentarily inconsistent but will be consistent eventually
- 6. You have to choose only two. In almost all cases, you would choose availability over consistency CAP Theorem 6
- 7. NoSQL (Not Only SQL) … ?? A NoSQL database provides a mechanism for storage and retrieval of data that employs less constrained consistency models than traditional relational databases. Motivations : Simplicity of design ; Horizontal scaling ; Availability. NoSQL databases are often highly optimized key–value stores intended for simple retrieval and appending operations, with the goal being significant performance benefits in terms of latency and throughput. Used for : Big Data and real-time web applications. 7
- 8. Why now ?? 8
- 9. Characteristic of NoSQL Large data volumes. Scalable replication and distribution (Horizontal scaling). Queries need to return answers quickly. Asynchronous Inserts & Updates. Schema-less. BASE / CAP Theorem. No Joins statement. No complicated Relationships Less administration time(less cost).
- 10. Types of NoSQL Databases NoSQL DB family includes several DB types: Column: HBase, Accumulo, Cassandra Document: MongoDB, Couchbase Key-value : Dynamo, Riak, Redis, Cache, Project Voldemort Graph: Neo4J, Allegro, Virtuoso
- 11. Data Model: Collection of key/value pairs Keys and Values can be complex compounds Designed to handle massive load No complex query filters All joins must be in the code Advantages Very fast Very scalable Simple model Able to distribute horizontally Very Predictable performance of O(1) Disadvantages Many data structures (objects) can't be easily modeled as key value pairs Key/Value Databases 11
- 12. Tables are similar to RDBMS, but semi-structured Based on Google’s BigTable Rows can have arbitrary columns Distributed and Decentralized High Availability & Fault Tolerance Tunable Consistency Column Databases 12
- 13. Document Databases 13 Inspired by Lotus Notes Central concept of a Document Documents encapsulate/encode data in some Encodings: XML, YAML, JSON, BSON
- 14. Graph Database 14 Based on Graph Theory -> G = (V, E) Designed for data that is well represented in a graph Social networks, public transport links, network topologies, road maps Nodes, edges, properties are used to represent and store data Graph relationships are query able
- 15. Which one should I choose ?
- 16. What’s best depends on your data
- 17. Priorities What types of queries do you need to support? How much data? Optimized for reads, writes, or updates? Versioning How separate is data from app? Will other applications need to access it in future?
- 18. And how you want to interact with it RESTful inteface Query API NonSQL query languages Via indexed values, keys, nodes File access
- 19. It too has disadvantages… Performance and scalability achieved at the expense of feature support No joins Grouping and ordering become more problematic No SQL No transactions Eventual consistency v/s Strict consistency Tools are often lacking
- 20. Summary NoSQL : Handle huge data. High availability with small cost. More data redundancy. High performance. Less administration time. Less standards. SQL : Good to solve ACID problems. Expensive. Less data redundancy. Increasing availability mean increasing cost. More standards. More administration.
- 21. Thank You !
Editor's Notes
- #6: Soft state : Data may be time-dependent on user interaction with possible expiration after a period of time. The data must be updated or accessed to remain relevant in the system.