Do XML-based Databases Live Up to the Hype?

douthitb asks: "I have recently started work as a contractor with a company developing/improving an application for exchanging large amounts of data. The current solution exchanges data via XML, but the data itself is stored in a SQL Server database. There is a concern about the overhead involved with wrapping and unwrapping the XML to get the data in and out of a relational database. The proposed solution is to use Tamino, an XML-based database. Neither I nor any of the other developers have any experience with Tamino, but the desired result is to remove the bottleneck of converting the XML back and forth. Does anyone have experience using Tamino (or any other XML-based database)? What benefits and/or difficulties did you have in using an XML database, as opposed to its relational counterpart? How large of a learning curve should be expected with a product like this? Do XML databases really live up to the hype? A similar topic was discussed on Slashdot way back when, so I was hoping to get some more up-to-date feedback on the subject." "Sales reps from Software AG, the makers of Tamino, were brought in to discuss the benefits of their product with us. They, of course, presented Tamino as the end all, cure all database system (it will even clear your acne and make you popular with the girls!). The management of the company I'm contracting with were basically eating out of the sales reps' hands, without asking any of the "tough" questions about what the product can do; I was less convinced. Doing some initial searching on the Internet, I have had trouble finding much information about Tamino outside of the Software AG website."

Comments

I've used Tamino and here's my story

[snowtigger]

A few years back, I was brought in to a small company to build their new software on top of the Tamino DB. XML was "the way of the future" and we were asked to use it as much as we could. Software AG promised that everything would be easy to program and that their software functioned perfectly. Software AG's sales rep used the fact that Tamino was used in production by (insert major national company here) as a major selling argument. I later found out from a friend working there that they had only evaluated Tamino, found it useless, and never used it in production.

Well, we did finish the software on time, but it was a complete nightmare. Software AG hardly gave us any straight answers (even though they charged big $ for customer support).

Tamino itself was missing a lot of features and seemed designed as a system for storing documents, totally lacking traditional database qualities (uniqueness, reliability, scalability, ...) We couldn't even get a reliable unique key from the database. The id we did get "could change" if we were to backup and restore the database. Tamino also scaled very badly with simple queries taking up to a minute on the fastest PC we could buy.

Needless to say, the software was thrown away and rebuilt with a reliable SQL database.

I would strongly discourage anyone from bilding an application on top of an xml database, especially Tamino. If you really want to build your application on top of an xml database, I would seriously ask myself why and what difference it would make. Also, if you really need an xml interface, choose an ordinary sql db that has a xml plugin.