What is Apache Cassandra?
Understanding Cassandra
Apache Cassandra is an open-source, NoSQL database designed to store data for applications that require fast read and write performance. With Cassandra, data is organized into keyspaces and tables. Keyspaces are collections of tables that you use to represent table groupings, such as different system components, applications, or environments. Each table in Cassandra has a schema. Schemas define the columns within a table, and the data type of each column.
Cassandra stores data within tables in rows. Each row in a table has a primary key which uniquely identifies the row within the table. Primary keys are composed of partition keys and optional clustering columns. Partition keys can be simple and made up of a single column, or rows can have compound partition keys composed from multiple columns. Rows also can have clustering columns, which is used to sort rows within the same partition.
Learn how Amazon Keyspaces (for Apache Cassandra), a serverless, fully managed, Apache-Cassandra compatible database service can help you easily run Cassandra workloads. The data modeling guide is available in the Amazon Keyspaces Developer Guide.
Cassandra Query Language (CQL)
You can read, write, update, and delete data from Cassandra by using the Cassandra Query Language (CQL). CQL is a flexible, SQL-like API that enables developers to execute data definition language (DDL) and data manipulation language (DML) statements. You use DDL statements to create and define resources. For example, the following DDL statement creates a table named books in a keyspace named bookstore with a primary key column of isbn.
Learn more about CQLCREATE TABLE bookstore.books (
isbn text,
title text,
author text,
year_of_publication int
PRIMARY KEY (isbn)
);You use DML statements to manipulate data in a table. For example, the following DML statement inserts a new row into books table.
INSERT INTO bookstore.books (isbn, title, author, year_of_publication,) VALUES (‘0101010101010’, ‘The Long River’, ‘Jim Sozeb’,’1994’);
Learn more about CQL in the CQL Language Reference for Amazon Keyspaces (for Apache Cassandra).
Open source community
As an active member of the Apache Cassandra community, AWS publishes code samples for a variety of programming languages to help new Cassandra developers get started. The Apache Cassandra community’s main annual event is ApacheCon. Below are videos from AWS presented sessions from previous ApacheCon conferences.
Getting started
Easy ways to explore Keyspaces