"There are still reasons why you might want to stick with a commercial vendor's offerings, some of which relate more to niche application needs like real-time, event-driven applications," Brand said.
"I think we'll also see a fairly aggressive push from vendors in trying to influence, if not control, the open source database development market. It's such a huge market that could potentially influence so many other market segments."
That said, Brand believes the days of databases themselves being valuable is "somewhat over", because the needs of users have evolved and the race is now on to control the business process layers of software, not just data structure and storage.
"The impact that open source databases have had on the industry is a reflection of just how critical and yet so worthless the database is considered to users who interact with an application and an interface," he said.
"Data can no longer be contained or controlled in the way we always thought it should have been, so a focus on data structure, storage, and management seems somewhat 'old fashioned'."
Brand said a paradigm shift in the way information is managed by the likes of Google is starting to make the traditional database somewhat irrelevant.And end users should be wary when deploying a free commercial database -which may cost tens of thousands for an enterprise version - of lock-in and over-zealous sales people, Brand said, "just waiting to put their hand in your pocket to grab whatever they can".
"Open source offerings at least give organizations the choice to pay only for support," he said. "If a product is considered stable and functionally rich enough then organizations will often pay for good support. It's ironic though that organizations that are not willing to pay high product licence fees will quite happily pay product support fees even though the implication there is that the product needs support."
More organizations are using "freeware, pledgeware, or supportware" not just for testing but for serious production deployments, Brand said and praised the open source MySQL which is being used in development and production "in most cases".
"This is because the development and test environments should be the same to avoid complications as a result of the intricacies of different products," he said.
"Unless the develop, test, and production environments are identical there's a fair chance organizations will run into curly interdependency problems that can take days, weeks, or even months in some cases to track down."
This is one of the reasons why Brand believes the functionally-locked or cut-down version of databases have generally been "very poorly" accepted by the developer community.
"Developers want access to fully featured products, not just a 'mini-me', hence the interest in MySQL," he said.
"The exception to this is in the use of embedded databases where data stores enrich client functionality. We don't see this happening though with any server-based, Web-based applications or any client/server apps being migrated off proprietary databases."
Brand said organizations should simply "get over" the single repository idea and make use of a limited number of technologies where they are most appropriate - including open source database products.
"Larger, more complex databases are not always the answer for improving information management practices, including security, ease of access, or semantic integrity," he said.
IBM DB2 Express-C
Memory limit: 4GB
CPU limit: Up to two processor cores and up to two dual-core processors on x86
Database limit: None
Instance limit: N/A
User limit: None
Redistributable: Yes, separate agreement
URL: www.ibm.com/db2/express (http://www.ibm.com/db2/express)
In January IBM announced the availability of DB2 Universal Database Express-C, community edition database at no charge. Big Blue's rationale for the move is to increase its commitment to the DB2 community. DB2 Express-C offers the same core DB2 data server in a smaller package designed for use in software development, deployment, redistribution and embedding within applications. A new public DB2 Express-C forum has also started free support. DB2 Express-C will run on Windows and Linux for 32 or 64-bit architectures, unlike the other 32-bit only free databases. Linux vendor Novell has announced it will bundle DB2 Express-C with its operating system. IBM is touting a "seamless" upgrade path from DB2 Express-C to the full-on enterprise DB2 Universal Database editions which support larger servers and clusters. The future "Viper" version of DB2 Express-C will include what IBM claims to be the industry's first hybrid data server for managing both relational and XML data.
Microsoft SQL Server 2005 Express Edition
Memory limit: 1GB
CPU limit: 1
Database limit: 4GB
Instance limit: N/A
User limit: 1
Redistributable: Yes
Supported platforms: Windows 2000 SP4, Windows Server 2003 SP1, Windows XP SP2
URL: http://msdn.microsoft.com/vstudio/express/sql/ (http://msdn.microsoft.com/vstudio/express/sql/)
While Microsoft's SQL Server continues to make inroads into the enterprise, it's free version, SQL Server 2005 Express Edition has been available for more than a year now. Being a Microsoft product, SQL Server Express is only available for Windows, but support for open standards - including native XML - is a core design feature. In addition to "wizards" for common tasks, SQL Server 2005 Express Edition has a new management and query editing tool. For developers there's "deep integration" with Visual Studio 2005 and Visual Studio data explorer can be used for designing schemas, adding data, and querying local databases. Database specifics aside, SQL Server sure threw down the gauntlet to the incumbent enterprise databases before they all went free.
Oracle Database 10g Express Edition (Oracle Database XE)
Memory limit: 1GB
CPU limit: 1
Database limit: 4GB
Instance limit: 1
User limit: None
Redistributable: Yes.
Platforms: 32-bit Linux and Windows
URL: http://oracle.com/technology/xe (http://oracle.com/technology/xe)
Larry Ellison drew even more attention to himself in October last year when Oracle announced a free version of its flagship database. The venerable tier-1 enterprise database now has a watered-down sibling. While Oracle XE is built from the same code base as the enterprise versions, for now it has the common scalability restrictions and is for 32-bit systems only. Oracle is pitching XE to developers, DBAs who need a "free starter" for training, and ISVs who can embed the software in their own products. Oracle Database XE can be installed on higher-capacity servers, but will only use its designated resources. The software ships with a management interface to monitor database activity and manage users, storage, and memory. Oracle claims XE applications will run unmodified on the enterprise editions.
Sybase Adaptive Server Enterprise Express Edition
Memory limit: 2GB
CPU limit: 1
Database size limit: 5GB
Instance limit: Unlimited
User limit: N/A
Redistributable: Sybase partners only
Supported platforms: Linux
URL: www.sybase.com/linux_promo (http://www.sybase.com/linux_promo)
With what began as a simple marketing ploy, Sybase started the free enterprise database revolution with Adaptive Server Enterprise (ASE) Express Edition. Only available for Linux, ASE Express Edition sports similar restrictions to its free competitors. However, the limits apply to each instance of ASE Express Edition so you can run many instances of ASE Express Edition on a machine; in total the individual instances could utilize more than one processor, more than 2GB of RAM, and manage more than 5GB of disk space. Optional support plans, including telephone support and named support contacts, are available from A$2,200 (US$1,680) per year.