Last checked and updated on 12 Jun 2026
What Is New in HSQLDB 2.2
HSQLDB 2.2 delivers significant enhancements in performance, SQL standards support, and overall reliability. This version focuses on refining the engine for modern application demands.
| Category | Key Changes |
|---|---|
| New Features | SQL:2016 support, new built-in functions, enhanced data types. |
| Performance | Faster aggregate queries, improved index usage, optimized caching. |
| Compatibility | Better JDBC 4.2 support, refined transaction control. |
| Bug Fixes | Resolved issues with constraints, subqueries, and transaction handling. |
What SQL standards are supported in 2.2?
HSQLDB 2.2 expands its support for SQL:2016 core features. This includes a broader range of temporal data handling and more sophisticated analytic functions.
You get better compliance with standard syntax for window functions and common table expressions (CTEs). In practice, this means your complex reporting queries will run more reliably and are easier to port from other databases.
How is aggregate query performance improved?
The engine now handles aggregate queries, especially those with GROUP BY and DISTINCT, much more efficiently. This is due to internal optimizations in how result sets are built and sorted.
You will notice the biggest speed gains on large datasets where these operations were previously a bottleneck. This matters because it directly reduces response times for dashboards and data analysis tasks.
What new functions can developers use?
Version 2.2 introduces several new built-in functions. These include string manipulation, mathematical, and date/time functions that align with the SQL standard.
For example, you can now use TRIM with more flexibility and new numeric functions for precise calculations. This saves you from having to implement custom logic in your application code.
Are there any critical bug fixes?
Yes, numerous bugs from previous versions have been resolved. Key fixes address issues with constraint enforcement, subquery execution plans, and transaction isolation under high load.
These fixes make the database more stable and predictable. You are less likely to encounter edge-case errors that can disrupt application flow or compromise data integrity.
FAQ
Is HSQLDB 2.2 fully compatible with JDBC 4.2?
Yes, compatibility with JDBC 4.2 has been enhanced. This includes better support for the JDBC API specifications, making it smoother to integrate with modern application frameworks.
Does this version change how database files are stored?
No, the underlying file format for persistent databases remains compatible. You can upgrade from previous 2.x versions without needing to convert your data files.
What is the most significant performance gain in 2.2?
The optimization of aggregate and sorting operations is the most noticeable improvement. Queries that use GROUP BY or window functions will see the largest reduction in execution time.
Are any features deprecated in this release?
The changelist does not highlight major deprecations for 2.2. The focus was on adding features and fixing issues rather than removing old functionality.
Can I use new SQL:2016 features like JSON_TABLE?
While SQL:2016 support is expanded, specific functions like JSON_TABLE may not be fully implemented. Check the latest documentation for the exact status of each feature.