Re: Recursive Queries

Поиск
Список
Период
Сортировка
От Joshua D. Drake
Тема Re: Recursive Queries
Дата
Msg-id 45B8D221.7050301@commandprompt.com
обсуждение исходный текст
Ответ на Re: Recursive Queries  (Gregory Stark <stark@enterprisedb.com>)
Ответы Re: Recursive Queries  (Gregory Stark <gsstark@mit.edu>)
Список pgsql-hackers
Gregory Stark wrote:
> "Martijn van Oosterhout" <kleptog@svana.org> writes:
> 
>> On Thu, Jan 25, 2007 at 11:08:14AM +0000, Gregory Stark wrote:
>>> b) I do want to be able to support depth-first searching too. I'm not sure how
>>> to reconcile that with the repeated-join conceptual model. We could always
>>> resort the entire result set after generating it but that seems like an
>>> unsatisfactory solution.
>> If you have a tuplestore storing the intermediate tuples for looping,
>> then surely the only difference between depth and breadth searching is
>> that for the former new tuples goes to the front of the tuplestore, and
>> the latter to the end.
> 
> That's basically how the existing patch approached the problem. It invents a
> new type of join and a new type of tuplestore that behaves this way. This has
> the advantage of working the way Oracle users expect and being relatively
> simple conceptually. It has the disadvantage of locking us into what's
> basically a nested loop join and not reusing existing join code so it's quite
> a large patch.

I believe our Syntax should be whatever the standard dictates,
regardless of Oracle.


Joshua D. Drake



-- 
     === The PostgreSQL Company: Command Prompt, Inc. ===
Sales/Support: +1.503.667.4564 || 24x7/Emergency: +1.800.492.2240
Providing the most comprehensive  PostgreSQL solutions since 1997            http://www.commandprompt.com/

Donate to the PostgreSQL Project: http://www.postgresql.org/about/donate
PostgreSQL Replication: http://www.commandprompt.com/products/



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Teodor Sigaev
Дата:
Сообщение: Re: unused_oids?
Следующее
От: Heikki Linnakangas
Дата:
Сообщение: Re: crash on 8.2 and cvshead - failed to add item to the