March 2015 Summaries

The latest version of the C# Driver for Apache Cassandra introduces support for manual paging and a more user-friendly routing API. It also adds lightweight transaction support to the Mapper and Linq components. Automatic fetching of limited rows in SELECT queries is now possible, with the option to retrieve the next page based on previous state. The PagingState property should be used carefully as it can expose vulnerabilities. Manual paging can be done using ExecutePaged() for Linq and FetchPage() for Mapper. The driver now makes it easier to handle routing keys, with examples provided for different types of statements. Lightweight transactions are supported in Linq and the Mapper. Version 2.5.1 is available on Nuget, with contributions from the community appreciated.

The upcoming 2.2 release of Cassandra aims to improve its permissions management by adding significant new functionality to the authentication and authorization subsystem. One major enhancement is the introduction of role-based access control (RBAC), which allows administrators to bundle related privileges together by granting them to roles, which can then be assigned to specific database users. This greatly simplifies permissions management for administrators and provides more flexibility in managing user access. The new RBAC system also supports inheritance of permissions from one role to another, allowing admins to create a deep structure of roles with fine-grained permissions without incurring a huge administrative burden. Additionally, the creator of a role is automatically granted permissions on it, enabling users with role-creation privileges to manage the roles they create.

Apache Cassandra users should be aware that join operations are now possible with the database, contrary to previous critiques. There are two primary methods for performing these joins: using Apache Spark's SparkSQL or DataStax provided ODBC connectors. While creating your own Cassandra and Spark combination clusters is possible, it's much easier to use DataStax Enterprise (DSE) as it bundles and certifies Spark with Cassandra in its analytics package. Additionally, DSE ships with a Weather Application Demo that demonstrates how DSE Analytics works. For more complicated join queries, refer to the online documentation.

Today, DataStax has announced the general availability of a new ODBC driver built on top of the Cassandra native protocol (CQL), which can be used free of charge with both open source Cassandra and DataStax Enterprise. Developed by Simba Corporation, the DataStax ODBC driver for Apache Cassandra is compliant with the latest ODBC 3.52 specification, runs on both 32 and 64-bit versions of Windows and Linux, and can be downloaded from their website. The driver enables integration with a broad array of tools for data processing, migration, analysis, and visualization by leveraging the power of both CQL and SQL. It serves as a simple integration point to access online data stored in Apache Cassandra, a massive, scale-out, always-on, distributed database built for cloud, mobile, and internet-of-things applications.

The article discusses the proper way to order data in Apache Cassandra, a distributed NoSQL database system. It highlights common mistakes made by new users when designing time series data models and provides solutions for these issues. The primary key design is crucial for ordering data correctly, as it determines how data is partitioned across nodes. Using a dummy partition key or the Byte Ordered Partitioner (BOP) should be avoided due to potential hot spots and unbounded row growth problems. Instead, proper partitioning and clustering keys should be used to allow efficient sorting and querying of data. The article also emphasizes the importance of understanding the limits of Cassandra's wide row model and adjusting table designs accordingly.