Re: Storing hierarchical information?

>yes, I am sorry, at this point in time we have not implemented
>concurrent access for multiple threads or multiple processes yet.

Doh! ;-) For something free, I certainly won't complain though!

>Depending on your expected traffic, this might also work out fine for
>you. The Java language provides object and method locking by simply
>declaring a method as synchronised.

This sounds like it would make writing a PHP-callable wrapper around db4o pretty simple. I might look into this. I'm thinking of doing something like this to make an XML-RPC interface to the UniVerse database (PHP -> Java using XML-RPC, Java -> UniVerse using the UniObjects API), doing this with db4o should be pretty similar.

>The description of your usecase sounds as if you could even share a
>lot of data between sessions. Only changing data would require
>special instances to be generated for each web client.

This is very true. Every client sees the exact same hierarchy, the only question is with what part of the hierarchy they see.

This thread has given me a few things to think about... Loading the whole thing into memory once and just querying it in memory is very appealing from a speed perspective, and I could probably do it without too many changes to the code. Using db4o is very appealing from the "Doing It Right" perspective since it seems pretty much tailor-made for this type of job. Even adding some attributes to the documents table to cache certain things is appealing since I don't have to make very many code changes, but it is clearly not the best thing to do.

• Dave Kimmel criscokid_at_v-wave.com ICQ: 5615049