HSQLDB vs LMDB
HSQLDB
hsqldb.orgLMDB
symas.comSide by side
| Figure | HSQLDB | LMDB |
|---|---|---|
| Price from | $8.33/mo | — |
| Free plan | Yes | — |
| Free trial | — | — |
| Open source | Yes | — |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | — |
| Self-hosted | Yes | Yes |
| Plans published | 11 | 2 |
| Spec score · Embedded Databases | 9.2 (#2) | 7.5 (#22) |
| Concurrency | The engine is multithreaded and offers lock-based, MVCC and hybrid transaction-control models. | Readers do not block writers, writers do not block readers, and multiple processes can open the same environment on one host. |
| Integrations | The project documents JDBC and ODBC connectivity and integration with OpenOffice.org and LibreOffice. | Symas reports integrations with OpenDKIM, Heimdal Kerberos, Postfix, Cyrus SASL, MemcacheDB, SQLite3, and Riak. |
| License | HSQLDB source and binaries use permissive BSD-based licenses, with separate terms for legacy Hypersonic SQL code. | Symas states that LMDB is part of OpenLDAP and is under the OpenLDAP license, basically a BSD-style license. |
| Support | Support options include a help forum, a user mailing list, bug and feature request trackers, paid SupportWare, and professional commercial support. | Symas offers fixed-price Gold or Enterprise source-level support and porting or professional services for LMDB users. |
| Transactions | The engine supports lock-based and MVCC transaction models and is fully multithreaded. | LMDB provides full ACID semantics with MVCC, reader/writer transactions, and deadlock-free serialized writes. |
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
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.