Last checked and updated on 09 Jun 2026
What Is New in HSQLDB 2.6
HSQLDB 2.6 delivers a significant update focused on enhanced SQL standard compliance, performance tuning, and expanded functionality for modern development needs.
| Category | Key Changes |
|---|---|
| New Features | SQL:2016 support, JSON functions, new data types, PL/SQL style procedures. |
| Improvements | Faster text table processing, better optimizer performance, enhanced compatibility. |
| Bug Fixes | Numerous corrections for SQL standard compliance and existing functionality. |
What SQL standard features were added?
This release pushes HSQLDB further towards full SQL:2016 core conformance. You get a lot more standard SQL out of the box.
Key additions include the JSON_OBJECT, JSON_ARRAY, and JSON_OBJECTAGG
functions for working with JSON data directly in your queries. The parser now supports a much broader range of
standard SQL syntax, making it easier to port applications from other databases.
How is text table processing faster?
Importing and exporting CSV files is significantly quicker. The underlying text table source processing engine was overhauled for better performance.
In practice, this means your ETL jobs or data loading routines that rely on text files will complete faster, especially with large datasets. This is a straightforward win for developers who use HSQLDB for data processing tasks.
What's new with stored procedures?
You can now create procedures using a syntax that is very similar to Oracle's PL/SQL. This includes features like
the FOR loop for easier iterative processing within the database.
This matters because it lowers the barrier for developers familiar with Oracle to use HSQLDB. You can write more complex logic directly in the database without having to context-switch to a completely different procedural language.
Were there any important syntax changes?
Yes, the parser was updated to handle a wider array of standard and compatible SQL syntax. This improves overall compatibility with applications written for other database systems.
Some older, non-standard syntax forms have been deprecated in favor of their SQL standard equivalents. The system will guide you with warnings, so it's a good idea to check your logs after upgrading.
FAQ
Does HSQLDB 2.6 have better JSON support?
Yes, it introduces several SQL standard JSON
functions including JSON_OBJECT, JSON_ARRAY, and JSON_OBJECTAGG, allowing
for native JSON manipulation within SQL queries.
Will my existing applications break when upgrading to 2.6?
Most should work fine, but it's
always wise to test. The release includes deprecation warnings for some old syntax, so check your application
logs for any messages after an upgrade.
What is the main performance improvement in this release?
The most noticeable gain is in text
table (CSV) processing speed, which is now significantly faster for both importing and exporting data.
Can I use Oracle-style PL/SQL in HSQLDB now?
Yes, the new supported procedure syntax is very
similar to Oracle's PL/SQL, including features like FOR loops, making it easier to port database
logic.
Is the SQL syntax more standards-compliant?
Absolutely. Version 2.6 adds extensive support
for SQL:2016 core features and corrects previous non-standard behavior in many areas, improving cross-database
compatibility.