Is HSQLDB reliable?

Is HSQLDB reliable?

Yes, HSQLDB is a robust, transactional, database engine with ACID properties and a mature code base. These same technologies are at the heart of PostgreSQL, MySQL, Oracle, DB2, MS SQL Server, etc. In addition, HSQLDB employs a transaction log with auto-recovery. An automatic backup file is also maintained if enabled. The end-user can supplement these measures by storing the database files in a folder protected by automatic backup software or cloud-sync services. It's also prudent to run database applications on a computer protected by an 'uninterruptable power supply' (UPS) or on a laptop with the battery installed. These measures avoid loss (rollback) of any buffered data in the event of a power failure. Speaking of buffered data, all transactional database engines employ a write-delay buffer to enhance performance. The buffer can be set to 0 seconds at the expense of write performance. HSQLDB uses a modest 500ms buffer by default, so new data is safely written to disk after a half-second delay. Base sets this write-delay buffer to 60 seconds for all 'embedded databases' files, which is excessive, but most folks can recover from the loss of one minute's productivity in the event of a power failure or similar event. In all cases, buffered data is written immediately to disk upon normal shutdown. Advanced, enterprise-level, reliability measures such as hot backups, clustering and replication, designed for 24/7 availability, are not available with HSQLDB 1.8 -- although hot backups are supported by HSQLDB 2.x, while clustering is oddly-enough a feature of H2 database.