XML File as database?

Question

Is it possible to use single XML file for Ruby on Rails as an ActiveRecord database?

Answer 1

No, AFAIK,

I would suggest you to use sqlite3 as database, since it's lightweight and small. If you want to generate XML from that, you can just use to_xml method :)

Answer 2

Read this stackoverflow posting for a rundown on this topic. The answer boils down to scalability and data integrity. At some point the data file will get big enough that it will need on-disk indexes, which are not directly supported in XML. Also, an XML file is not transactional - it has no logs. To implement a transactional storage in an XML file you would have to implement a DBMS, and create supplemental transactional log and index files. This is almost certainly far more trouble than it's worth.

Answer 3

I'd say it was possible, but you really wouldn't want to do it!

It would involve writing a new XML ActiveRecord adapter that would issue XPath (presumably) queries against your file where the other adapters would generate SQL. I suppose you'd also need migrations to maintain XSD or DTD files.

It's horrible. Don't do it.