User Tools

Site Tools


"Free Database" Comparison

This isn't meant to be a comprehensive discussion of all databases. Instead, its a comparison of key features1) in the free offerings from commercial vendors.

Oracle XE MS SQL Express IBM DB2 Express-C
Feature Free Commercial
Vendor-provided patches & updates No Yearly Fixpacks
Free for production environments Yes Yes Yes Yes
Max data size 4gb 4gb Unlimited
Max RAM usable 1gb 1gb 2gb 4gb
Max # CPUs 1 1 2 4
Max # concurrent connections none 2) 5 none none
Vendor 24/7 support No No No Yes
Non-disruptive DB upgrade No Yes Yes n/a
Clustering available No No No Yes
Hi availability No No No Yes
DB Upgrade price $5800/cpu/yr $3500/svr/yr $3k/svr/year
DB Upgrade complexity Medium Medium Low
XML capabilities Low High High
XML-based data mapping to code Low ?? ??


  • I gave DB2 two columns because it has an interesting licensing model. All of the commercial features exist in the free database; they're just disabled by default. Purchasing a licence key activates them.
  • DB2 Express-C allows more RAM, disk, and CPU to be used by the database than its competition. That means I can run larger queries against more data with DB2 than with other products.
  • All three databases support XML processing. Oracle XE seems to have the lowest-level support, meaning that I must do more work to setup and run an XML-based project. DB2 and MS SQL seem to have much better support, with the ability to map XML elements to table columns, and the ability to use XQuery to retrieve data. (I'm unsure about the complexity of round-trip engineering from business objects to the database and back).
1) the key features that I am personally interested in
2) default=20
/home/cfreyer/public_html/data/pages/technology/databases/free_database_comparison.txt · Last modified: 2010/07/28 11:53 by Chris Freyer