Re: Tree structure table normalization problem (do I need atrigger?)
От | Frank Joerdens |
---|---|
Тема | Re: Tree structure table normalization problem (do I need atrigger?) |
Дата | |
Msg-id | 3A3F6006.ECDE92AE@joerdens.de обсуждение исходный текст |
Ответ на | Re: Tree structure table normalization problem (do I need a trigger?) (Tulassay Zsolt <zsolt@tek.bke.hu>) |
Ответы |
Re: Tree structure table normalization problem (do I need
atrigger?)
Re: Tree structure table normalization problem (do I need atrigger?) |
Список | pgsql-sql |
Tulassay Zsolt wrote: [ . . . ] > The SQL stuff of that nested set structure is fairly easy, I wrote some > quick'n'dirty plpgsql functions that will do inserts, updates, deletes > from the tree, display level number etc. What scared me about it in particular was one scenario where you try to delete a subtree. This would normally leave a gap, since the structure is based on the worm's ability to get from one node to the next with an increment of just 1. Once you had a subtree deleted, you'd either would have to have the worm leap-frog (a leaping frog-worm?!! :)) the gap or update an entire half of the tree to close it . . . then my brain started to hurt and I gave up. > I can send it to you if you like (please allow a few days since I > have several exams at the university this week). Sure, I'd like to have a look at it! Thanks, Frank
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