Re: Problem with Nested Sets

>> the "ON UPDATE CASCADE" part, and

i'm not sure about the "REFERENCES" part either <<

These are Declarative Referential Integrity (DRI) actions. You will need to read about them in detail, but when the referenced table changes, the referencing table also changes automatically.

>> [level] I thought I could put it as a column for performance, as it
is easy to just add it when adding a child. <<

But then you need a constraint to be sure that it is always correct. So why not compute it? It will save space, run a little faster than a disk read amd always be correct.

>> think that maybe I should use materialized paths instead of nested
sets, but I don't know much about it. <<

Since you are searching text and not doing math on the data, I agree.

>> Moreover I live in France in shipping from USA is probably high, and
it's not like my understanding of english is perfect. <<

Well, you can get SQL ADVANCE in French. I do not know if TREES & HIERARCHIES will be translated. Received on Thu Feb 24 2005 - 09:20:16 CST