The lowdown on databases with XML
What are they?
Databases designed to store XML documents intact, in their native form. This means that documents can be stored, indexed and accessed without having to 'shred' them into relational database tables. This saves time, code and storage space.What are they good for?
Any application that uses XML documents as a data storage format. Most prominent among these are document, content and forms management applications, as well as Web portals and e-commerce applications using XML electronic data interchange.How big can they get?
Several XML databases support document stores of more than a terabyte.How much do they cost?
Depending on how much assembly you're comfortable with, they range from free'for the Apache Software Foundation's Xindice'to tens of thousands of dollars per CPU in the case of Software AG's Tamino.Must-know info?
The query language standards for XML databases are just now being formalized, and there are a lot of very small companies in the market. Oracle and Microsoft have non-native products for XML storage, which could be enough for many applications. But if you don't have to use XML for your applications, you won't need an XML database.