What is it?
According to IBM, the IT industry is moving towards a mixed
model, with commercial tools built on top of open source
frameworks. Sun Microsystems seems to agree. Both supply the same
small-footprint, pure-Java, open source database.
Sun calls it
Java DB and ships it with the
Java Enterprise System and
Solaris Enterprise System. IBM calls it
Cloudscape and has added a driver for the
DB2 Universal Database. It is also shipped with
the Websphere application server.
Cloudscape and Java DB are full implementations of the Apache
Software Foundation's Derby project. Like Derby, they can run on
any system with a Java Virtual Machine, enabling developers to
"write once, deploy anywhere", but both include add-ons to draw the
user gently from the open source to the proprietary
environment.
Where did it originate?
Cloudscape Inc was founded in 1996 to develop a Java database.
In 1999 it was acquired by Informix, which was taken over by IBM in
2001. IBM developed Cloudscape as an embedded Java database, before
handing it over to the Apache Software Foundation in 2004. Sun
began supplying Java DB in 2006.
What's it for?
Despite its small size (about 2Mbytes), Derby/Cloudscape/Java DB
has standard relational database functions, such as multi-user
support, indexes, triggers, transactions and failure recovery.
It can be used as an embedded database or in client
applications, being particularly suited to laptops and PDAs, where
a small, robust database is needed. It is also suitable for rapid
Java application development and testing. But it scales to hundreds
of users, and IBM offers easy migration to DB2.
Cloudscape/Derby is also used to provide SQL functionality
within applications developed under the IBM-backed Eclipse
initiative.
Sun uses Java DB as an embedded application and developer
platform in Java Enterprise System 4.0. It is supported by Netbeans
5.0 and Java Studio Enterprise.
What makes it special?
IBM says, "Cloudscape's simplified deployment and robust
self-management features eliminate the need for a database
administrator." This, along with its small size, means it can be
distributed within browser-based applications that need a local
data store. Implemented as a Java JAR file, Cloudscape/Derby
becomes part of the application that is running it, although it is
hidden from the user.
How difficult is it to master?
Straightforward for Java developers who are comfortable with
SQL.
Where is it used?
In independent software suppliers that want to sell to both
large and small users without having multiple databases. The same
applications can be supplied with either Cloudscape or DB2, without
porting. It is also used in applications requiring long-term
persistence or short-term caching, such as UDDI registries and
shopping carts.
What systems does it run on?
AIX, Linux, OS/400, Sun Unix, Windows, z/OS.
What's coming up?
The future of Derby will be covered at ApacheCon Europe 2007,
which takes place in Amsterdam in May.
www.eu.apachecon.com
Training
Cloudscape documents and tutorials
Java DB demos and links
Apache Derby quick start
Rates of pay
Websphere developers with Cloudscape and other Java skills can
earn £35,000 or more.
Salary survey