Oleg Broytmann wrote: > Hello. Another round of "have I got it right". Very nice summary. I think all of your descriptions are basically correct, except for the following one. > OODB disadvantage: you have to manipulate with objects; for example, if you > need to select a subset you have to iterate over the entire set of objects. Clever indexing and automatic maintenance of those indexes means the database can easily return subsets without iterating over the entire set of objects. Schevo does this for keys, indexes, and references. -- Patrick K. O'Brien Orbtech http://www.orbtech.com Schevo http://www.schevo.org Pypersyst http://www.pypersyst.org PyDispatcher http://pydispatcher.sourceforge.net