The following table describes the comparison between several open source databases. The comparison will cover: HSQLDB, H2, PostgresSQL, MySQL, Derby in terms of their limitations and strength. This analysis could help to select database for our project.

 

	PostgreSQL 8.2	MySQL 5.0	Apache Derby 10.3	HSQLDB 1.8	H2
OS support	First windows supported version, only support linux and windows, special compilation requires for other platforms	Supports Windows/Linux/Unix/Mac OSX	Any OS that can run Java	Any OS that can run Java	Any OS that can run Java
Documentation	Full pre and post installation documentations	Extensive pre and post installation documentations	Extensive pre and post installation documentations	Full pre and post installation documentations	Extensive pre and post installation documentations
License	BSD License - Free	Depends - GPL for open source or Commercial for commercial	Apache License v2 - Free	BSD License - Free	Modified MPL - Free
Maximum Database Size	Unlimited	Unlimited	Unlimited	Unlimited (depends on memory)	Unlimited (depends on memory)
Maximum Number of Tables	Unlimited	Unlimited	Unlimited	Unlimited (depends on memory)	Unlimited (depends on memory)
Maximum Table Size	32 TB	64 TB	Unlimited	8 GB	?
Maximum Row Size	1.6 TB	8 kB	Unlimited	Unlimited (depends on memory)	?
Maximum Field Size	1 GB	255 B	2 GB	Unlimited (depends on memory)	?
Maximum Rows per Table	Unlimited	Unlimited (Limited by tablespace of 64TB)	Unlimited	Unlimited (depends on memory)	Unlimited (depends on memory)
Maximum Columns per Table	250 - 1600 depending on column types	1000 columns	1012 columns	Unlimited (depends on memory)	Unlimited (depends on memory)
Maximum Indexes per Table	Unlimited	64 indexes	32767 indexes	Unlimited (depends on memory)	Unlimited (depends on memory)
Indexes	32 fields - B-Tree, R-Tree, GiST, and Hash	16 fields - B-Tree	16 fields	?	?
Interfaces	ODBC, JDBC, C, etc.	ODBC, JDBC, C, etc.	JDBC	JDBC	JDBC
Transactional	ACID-compliant	InnoDB type tables only - ACID-compliant	Yes	?	Yes
Bind Variables	Yes	Yes	Yes	?	?
Stored Procedures	Yes - SQL, PL/Tcl, PL/pgSQL	Yes	Yes	Yes	Yes
Trigger	Yes - SQL, PL/Tcl, PL/pgSQL	Yes	Yes	Yes	Yes
Row Level Locking	Yes	Yes	Yes	?	Yes
Timeout	Yes	No	Yes - deadlock detection and timeout	Yes	Yes
Error Code	Yes	Yes	Yes	Yes	Yes
Date Time	Broad range of date/time formats	Broad range of date/time formats	Broad range of date/time formats	Broad range of date/time formats	Broad range of date/time formats
Scalability/SMP	Each connection uses one CPU, but spread the processes of different connections across available CPUs	SMP is supported by using OS threads. All connections are executed in one thread, queries are not using multiple CPUs	Yes, embedded engine does all work in client threads	Multithread listener, but execute queries one at a time
Load Balancing	Select queries are distributed among the master and slave servers in random manner. Other queries are executed on master and replicated to slaves	MySQL clusters - handle transactions in a round robin manner	N/A	N/A	N/A
Replication	Slony1 replication solution, not core	Master-Slave replication and Chained replication	Master-Slave replication with manual fail-over	N/A	N/A
Online Backup	Write-ahead log and PostgreSQL point-in-time recovery, also Hot Standby System	Online Backup with Mysqldump, InnoDB Hot Backup (commercial add-on), MySQL Clusters commited log	Yes - Online backup utility	Yes - backup manually data files and redo logs	Yes - built-in tool
Cluster	PGCluster	in-memory, shared-nothing, replicatied to 4 replicas. If 1 node fails, currenct transaction fails even all other nodes survive	N/A	N/A	Yes?
Ease of Embedding in Java-based Application	Needs a lot of customizations	Can use MySQL Embedded	Almost no customization requires	Almost no customization requires	Almost no customization requires, and run as server after embedded