Re: usage for 'with recursive'?
От | hubert depesz lubaczewski |
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Тема | Re: usage for 'with recursive'? |
Дата | |
Msg-id | 9e4684ce0703020028i5def633ct510b7d3f1cb9bbbc@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: usage for 'with recursive'? (Kenneth Downs <ken@secdat.com>) |
Ответы |
Re: usage for 'with recursive'?
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Список | pgsql-general |
On 3/1/07, Kenneth Downs <ken@secdat.com> wrote: > Better? I think perhaps different. There is materialized path, which > requires a very problematic unlimited-length column to hold the path, > and there is upper/lower bounds, which again requires client-side > row-by-row processing. Both have the unpleasant problem that changes to > one row may affect many others. there are also other approaches. i know that they are not that well known, but there are, and they allow many things to be done with very simple queries. i use a solution which basically allows me to query every kind of tree-structure data without loops or recursion. drawbacks are 2 and are very limited: 1. it uses some triggers 2. it has some (slight in my opinion) overhead. i wrote an article about it here (http://www.depesz.com/various/various-sqltrees-implementation.php). it's in polish, but has lots of examples so should be easily readable. depesz
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