Jun 13, 2009, 13:57 by ianb
Great stuff on the nested interval model and the sql standard way of using trees, neither of which I'd used before.
Trees in the Database: advanced data structures
Lorenzo Alberton (Jun 13, 2009)
Talk at Dutch PHP Conference 2009 (English - US)
Storing tree structures in a bi-dimensional table has always been problematic. The simplest tree models are usually quite inefficient, while more complex ones aren't necessarily better. In this talk I'll briefly go through the most used models (adjacency list, materialized path, nested sets) and introduce some more advanced ones belonging to the nested intervals family (MPTT, Continued Fractions, Farey algorithm and other encodings).
I'll describe the advantages and pitfalls of each model, some proprietary solutions (e.g. Oracle's CONNECT BY) and one of the SQL Standard's upcoming features, Common Table Expressions.
Quicklink: http://joind.in/585
Comments
Jun 13, 2009, 14:04 by marce!
Really interesting stuff. Sometimes it was a bit hard to keep up, but all in all a good talk.
Jun 13, 2009, 14:15 by Anonymous
Interesting stuff, you need to work on your nervous of steel a bit. But it was a well prepared and enjoyable talk !
Jun 13, 2009, 14:32 by jach
Very interesting stuff. Probably need to read up on this when I get home...
Jun 13, 2009, 14:44 by Gerb
This was a good one, nice to get an overview of all the various tree-structures. Proceeding at top speed, which was good I think, but would like to review all of this at home on my own time... Maybe some more links next time? In terms of content: grrreat!
Jun 13, 2009, 20:02 by Anonymous
Very good talk about varying tree-structures! The information was very well explained, with tables and graphs. However, it could use less SQL query examples. Yes, we were told, that we don't need to read all of it.. well, maybe then don't show all of it.
it seemed Lorenzo was a bit nervous, which made him sometimes a bit hard to follow. However, there was no need to be nervous (!!), since the talk gave plenty of good informationthat will certainly be put to good use here! :)
Jun 13, 2009, 20:07 by Anonymous
Fast paced talk, and worth attending. Lots of pragmatic examples that illustrated the points well. The only thing that could be smoothed out would be the sections illustrating dividing algorithms on the graph but it just needs some refining.
You're a better speaker and your english is better than you seem to think, so just relax and have fun with it. :)
Jun 13, 2009, 23:36 by nemo
Definitely good. Not many people use to talk about alternative trees representation. That was good and very interesting to know that some DMBS already have some of those things implemented.
Jun 14, 2009, 20:58 by derick
Good talk, but I think the nested intervals was perhaps a bit too complex to explain in such a small time frame.
Jun 14, 2009, 21:24 by rickmb
Part of this stuff went way over my head, especially at this late point in the con. Somewhat nervous, flat presentation made it even harder to follow.
But the talk was well prepared, well structured and extremely informative by a speaker who clearly knows what he's talking about.
Jun 14, 2009, 21:24 by Anonymous
Interesting material, well prepared and presented.
Jun 15, 2009, 07:38 by Dynom
Most of the structures I knew about, but never used it. Seeing some examples was actually quite helpful. You where a bit nervous but still the talk was very good. Your presenting skills exceed those of a few speakers I've seen that have more experience. Really good !
Jun 15, 2009, 08:32 by mihahribar
English was a bit of a problem, but other than that very nicely presented. Thanks for all the great ideas regarding tree structures. I'm sure I would not found most of the ideas you presented on my own. Was a nice ending to a great conference!
Jun 13, 2009, 13:55 by hvdklauw
At the beginning you where a bit hard to understand, try to articulate better.
I liked the whole explanation about what a tree actually is, and the examples about solutions on how to handle inner node deletions was very nice.
Wow, good thing I knew a bit about adjacency list and the nested set, because it got rather complex with the nested interval model.