EJDB2 vs HSQLDB
EJDB2
github.com
HSQLDB
hsqldb.orgSide by side
| Figure | EJDB2 | HSQLDB |
|---|---|---|
| Price from | Free | $8.33/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| iOS | Yes | — |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 11 |
| Spec score · Embedded Databases | 8.5 (#4) | 9.2 (#2) |
| License | The repository describes EJDB2 as published under the MIT license. | HSQLDB source and binaries use permissive BSD-based licenses, with separate terms for legacy Hypersonic SQL code. |
| Product | EJDB2 is an embeddable JSON database engine written as a C library. | HSQLDB is a Java-based relational database engine with in-memory and disk-based tables, supporting embedded and server modes. |
| Support | The project README says its issues tracker is disabled and welcomes contributions and pull requests. | Support options include a help forum, a user mailing list, bug and feature request trackers, paid SupportWare, and professional commercial support. |
Plans
HSQLDB
- Developer subscription$100 a year
- Basic Corporate subscriptionPrice not published
- Premier Corporate subscription$2,500 a year
- HSQLDBFree
- HSQLDB softwareFree
- Developer SupportWare$100 a year
- SupportWare Developer subscription$100 a year
- Basic Corporate SupportWare$500 a year
- SupportWare Basic Corporate subscription$500 a year
- Premier Corporate SupportWare$2,500 a year
In their own words
EJDB2
EJDB2 is a free, MIT-licensed JSON database engine implemented as a C library for embedding in applications. It stores data in a single file, using the IOWOW persistent key/value storage engine. Its JQL query language supports filtering, data modification, collection joins, projections, sorting, indexes, and options to skip, limit, or count results; online backup is also listed. For network access, the standalone jbs server provides HTTP REST and WebSocket endpoints. The server supports TLS 1.2, can require an access token in the X-Access-Token HTTP header, and offers a write-ahead-log option for durability. EJDB2 provides a C11 API and lists macOS, iOS, Linux, Windows, and self-hosted availability. The repository links to language bindings and tags the project with C, Dart, Flutter, Java, Node.js, React Native, and Swift, but its changelog says only Java and Node.js bindings are maintained after a 2025 cleanup. The project README says its issues tracker is disabled and welcomes contributions and pull requests. The listed plan is EJDB2 at free.
HSQLDB
HSQLDB is a Java-based relational database engine for embedded or server use, with both in-memory and disk-based tables. It supports SQL:2023 core features and many optional features, plus lock-based and MVCC transaction models; the engine is fully multithreaded. Listed capabilities include JSON constructor functions, CSV loading and unloading, temporal system-versioned tables, row-level access control, and log-based replica synchronization. It includes a command-line SQL tool and simple GUI query tools. The latest official release listed is version 2.7.4, compatible with JDK 8 and above, and packages include Java 11 module jars as well as Java 8 jars for HSQLDB and SQL Tool. HSQLDB is self-hosted, with high availability, read replicas, and JSON data support listed. Its default combined limit for CACHED tables is 8TB, extendable to 256TB with a connection property; each TEXT table is limited to 256GB, and memory tables depend on available memory. The software is free to use in commercial products when license terms are met; its licenses are based on the new BSD License. The HSQLDB plan is free. A Developer subscription is $100 a year; Premier Corporate is $2,500 a year at the base level. Support options include community channels and paid commercial support.