2. 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
3. Primary Interfaces for objects/data
The Cassandra CLI (command Line Interface)
The Cassandra CQL (Cassandra Query
Language) interface
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4. The Cassandra Command Line Interface (CLI)
Originalinterface designed to create objects
(e.g. column families), input, and manipulate
data
5. The Cassandra Query Language (CQL) Utility
Utility
used to create objects/manipulate data
using a SQL-like language
6. 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.
7. 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
8. 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