ClickHouse 26.9: New Limits, Tokens, and Faster Queries

ClickHouse Evolves: Data Control and Security Enhanced

The ClickHouse 26.9 release is a robust iteration, packed with features that address common database challenges and enhance developer productivity. The introduction of conditional boundaries for LIMIT is particularly noteworthy, offering a level of granular control over query results that is rare in the SQL landscape. This, combined with the new CREATE TOKEN functionality, significantly bolsters security and operational flexibility, allowing for more precise credential management and reducing the attack surface. The ongoing expansion of PromQL support is also a strategic move, positioning ClickHouse as a more compelling solution for time-series data and monitoring use cases, especially with its integration into ClickHouse Cloud. However, the complexity introduced by advanced features like conditional LIMIT, while powerful, might require a steeper learning curve for less experienced users. Furthermore, while the article highlights performance optimizations, a deeper dive into specific benchmarks and the impact of these optimizations on various workloads would be beneficial for users planning upgrades. The private preview status of PromQL also indicates that its full integration and stability are still under development, which might temper immediate adoption for critical production environments relying heavily on PromQL.

Key Points

• ClickHouse 26.9 introduces conditional boundaries for LIMIT clauses, allowing for more precise control over result sets based on value conditions, a novel feature for SQL databases.
• A new CREATE TOKEN command enables the creation of time-limited, privilege-restricted credentials, enhancing security by avoiding the exposure of main user passwords.
• Enhanced PromQL support is now in private preview on ClickHouse Cloud, facilitating the storage and querying of metrics within ClickHouse.
• Performance optimizations have been implemented, including faster min, max, and count queries, and disk spilling for high-cardinality DISTINCT queries.
• Arithmetic operations between DateTime and Time values are now supported, with configurable overflow behavior (throw, saturate, ignore).
• The release includes a significant number of bug fixes (464) and performance optimizations (135), alongside 56 new features, reflecting active community contribution.

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📖 Source: ClickHouse release 26.9