Changwon Nati Univ. ISIE 2001 CSCI5708 NoSQL looks to become the database of the Internet By Lawrence Latif Wed Dec Nhu Nguyen and Phai Hoang CSCI 5708 – Architecture and Impl. Of DBMS Prof. Shashi Shekhar

1 Traditional DBMS vs NoSQL  Traditional DBMS –Structured and organized data –Data and its relationships are stored in separate tables.  NoSQL –Stands for Not Only SQL ( ≠ Don’t use SQL Language) –Flexible schema –Key-Value pair storage –Eventual consistency rather ACID property –Unstructured, messy and unpredictable data –Prioritizes high performance, high availability and scalability

2 History of NoSQL  1998: –Carlo Strozzi used the term NoSQL to name his lightweight, open-source relational database.  Early 2000s: –NoSQL fell out of favour in the early 2000s. –Hosting providers such as Dedipower promoted it as an alternative to traditional db.  Nowadays –Web giants such as Amazon, Google, Twitter, Ebay and Facebook already use NoSQL implementation.s to power customer facing parts of their businesses.

3 What kind of NoSQL?  Key/Value or ‘the big hash table’. –Using Hash table Data model: (key, value) pairs Operations: Insert(key,value), Fetch(key), Update(key), Delete(key) –Ex: Amazon Dynamo, LinkedIn Voldemort  Column Family Store –Still keys but point to multiple columns –Ex: Cassandra, HBase  Document database –Ex: CouchDB, MongoDB  Graph Database –Ex: Neo4J, InfoGrid, Infinite Graph

What kind of NoSQL?  Object Databases –Ex: Versant  RDF Databases –BigTable, Apache Hbase 4

Limitations of NoSQL relative to RDBMS  ACID transactions (strong consistency)  May not support join, range query  Facebook and Twitter were built on mySQL 5

6 Example: Apache Cassandra  Free, open source, distributed storage  Exists within the Apache family  Originally developed at Facebook  Column-oriented data model  Uses Apache Thrift as it’s API –keyspace.getSlice(key, “column_family”, "column") –keyspace.getSlice(123, new ColumnParent(“rockets”), getSlice Predicate());

7 Hashing in Cassandra  Partition using consistent hashing –Keys hash to a point on a fixed circular space –Ring is partitioned into a set of ordered slots and servers and keys hashed over these slots  Nodes take positions on the circle.  A, B, and D exists. –B responsible for AB range. –D responsible for BD range. –A responsible for DA range.  C joins. –B, D split ranges. –C gets BC from D.

References  NoSQL looks to become the database of the Internet, Inquirer, Dec osql-looks-database-internethttp:// osql-looks-database-internet  NoSql, Wikipedia 8

9 Thank you