HSQLDB 2.2.5

Major Features:

1. General
   • Original code, based on in-depth study of database theory and the SQL Standard
   • Ahead of other open-source solutions in supported SQL features
   • The fastest overall open-source SQL implementation for small and medium sized databases
   • Three transaction control models, including lock based and MVCC models
   • Fully multithreaded
   • Compact code footprint
2. JAVA
   • 100% Java
   • Support JDK 1.1.x, 1.2.x, 1.3.x, 1.4.x, 1.5.x, 1.6.x in HyperSQL 1.8.1 and 1.5.x and 1.6.x in HyperSQL 2.0
   • Extensive JDBC interface support with batch statement and scrollable ResultSet functionality
   • Updatable, insertable ResultSet functionality
   • Full JDBC DatabaseMetaData and ResultSetMetaData support
   • User-defined Java stored procedures and functions, including aggregate functions
   • Supports procedures with multiple INOUT params, returning multiple ResultSets, and functions returning ResultSet and Array objects
   • Java triggers, including synchronous and asynchronous execution
   • Full support for CallableStatement and PreparedStatement, including batch execution to speed up data processing
3. SQL
   • Relational Database Management System, which can store Serializable Java objects
   • Very extensive support for SQL:2008 Standard syntax, including most optional features
   • Supports all base data types of the SQL Standard, including BINARY, BIT, BOOLEAN, date-time, INTERVAL, BLOB, CLOB
   • Supports datetime arithmetic with and without time zone
   • Full support for powerful INTERVAL expressions, such as (CURRENT_DATE - 3 MONTH)
   • Supports user-defined DOMAIN types, including type constraints
   • Supports ARRAY objects of other data types with full syntax allowing access and conversions
   • Fast SELECT, INSERT, DELETE, UPDATE operations
   • MERGE statement allows single or multiple INSERT or UPDATE depending on existing data
   • INNER, LEFT OUTER, RIGHT OUTER and FULL joins
   • NATURAL, USING and UNION joins
   • LATERAL and UNNEST in joins
   • UNION, EXCEPT, INTERSECT, including use of parentheses, limits and offsets, ALL, DISTINCT and CORRESPONDING keywords
   • Scalar (single value) SELECTS, row, table and correlated subqueries including IN, EXISTS, ANY, ALL
   • Views and temporary tables
   • Updatable, insertable into, deletable views
   • Primary key, unique and check constraints on single or multiple columns 
   • Referential Integrity (foreign keys) on multiple columns with full cascading options (delete, update, set null, set default)
   • ORDER BY, GROUP BY, HAVING, FETCH (LIMIT) and OFFSET 
   • COUNT, SUM, MIN, MAX, AVG and statistical aggregate functions
   • Full support for SQL expressions such as CASE .. WHEN .. ELSE .. , NULLIF , BETWEEN, MATCHES, etc.
   • Extended SQL standard autoincrement IDENTITY column
   • Extended SQL standard support for sequences
   • SQL standard GENERATED columns calculated using other columns and function calls
   • Very extensive set of built-in functions
   • Transaction COMMIT, ROLLBACK and SAVEPOINT support
   • Multiple schemata per database
   • Triggers as blocks of SQL statements, including IF conditions
   • INSTEAD OF triggers which enable insert, update and delete on several tables with a single statement
   • SQL user-defined stored procedures and functions with full SQL procedural language support
   • SQL procedures can return multiple ResultSet objects
   • SQL user-defined aggregate functions
   • Database security with passwords, user rights and roles with GRANT and REVOKE
   • Table level DELETE privileges and column level SELECT and UPDATE privileges
   • Extensive set of ALTER TABLE commands, including change of table column type
   • Full set of SQL Standard INFORMATION SCHEMA views
   • Query optimizer can use indexes for AND, OR, IN predicates, also ORDER BY, MAX, MIN 
4. Persistence
   • In-memory tables for fastest operation
   • Disk based tables for large data sets
   • Text tables with external file data sources such as CSV files can be used as SQL tables
   • Fast CLOB and BLOB storage up to 64 TB with no memory limit on individual LOB size
   • Disk tables (CACHED TABLE) up to 256GB and text tables up to 2GB each
   • Size of each string or binary item only limited by memory
   • Fast startup and shutdown with internal incremental backup feature
   • Online and offline backup capability
   • Database dump as SQL script with or without data
5. Deployment
   • Embedded (into Java applications) and Client-Server operating modes
   • Three client server protocols: HSQL, HTTP and HSQL-BER - can run as an HTTP web server - all with SSL option
   • Can be used in applets, read-only media (CD), inside jars, webstart and embedded applications
   • Multiple databases per JVM
   • ODBC support
6. Utilities
   • SQLTool, powerful and compact Java command line tools for database management, supports most leading databases
   • Two simple GUI database management tools
   • Transfer tool for conversion of databases to / from other popular database management systems
   • Test / script utility that can run SQL scripts with user-defined checks

Enhancements:

• Fixed UNNEST in subquery
• Fixed issue with INFORMATION_SCHEMA.ELEMENT_TYPES view
• Fixed missing exception when table functions were used as SELECT items
• Fixed regression with server ACL file load
• Fixed issue with query not compiling with certain types of IN predicate
• Added support for UNNEST with multiple ARRAY args
• Added SYSTIMESTAMP function
• dba privilege required for LOAD_FILE function
• Improved handling of misconfigured external logging platforms
• Improved query speed for some joins
• Improved parameter type allocation for IN lists
• Minor improvements

Requirements:

• Mac OS X