Cassandra Essentials Tutorial SeriesManaging Objects andData in ApacheCassandra
Agenda Primary interfaces for managing objects and data The CQL and CLI utilities What is CQL? CQL Basics Examples of using CQL and the CLI Where to get Cassandra
Primary Interfaces for objects/data The Cassandra CLI (command Line Interface) The Cassandra CQL (Cassandra Query Language) interface 1 6 2 5 3 4
The Cassandra Command Line Interface (CLI) Originalinterface designed to create objects (e.g. column families), input, and manipulate data
The Cassandra Query Language (CQL) Utility Utility used to create objects/manipulate data using a SQL-like language
The Cassandra Query Language Objects such as keyspaces, column families, and indexes are created, altered, and removed with RDBMS-like CREATE , ALTER, and DROP Data is inserted, changed, and removed with DML INSERT, UPDATE, and DELETE commands Data is queried with the SELECT command CQL has some current limitations and does not support operations such as GROUP BY, ORDER BY, etc.
Specifying a Data Consistency Option in CQL Cassandra offers tunable data consistency Choose between strong and eventual consistency (All to any node responding) depending on the need Can be done on a per-operation basis, and for both reads and writes Handles Multi-data center operations Done with the USING CONSISTENCY clause Writes Reads Any One One Quorum Quorum Local_Quorum Local_Quorum Each_Quorum Each_Quorum All All
Where to get Cassandra Go to www.datastax.com DataStax makes free smart start installers available for Cassandra that include: The most up-to-date Cassandra version that is production quality A version of DataStax OpsCenter, which is a visual, browser- based management tool for managing and monitoring Cassandra Drivers and connectors for popular development languages Same database and application Automatic configuration assistance for ensuring optimal performance and setup for either stand-alone or cluster implementations Getting Started Guide