Re: Display of text fields
От | Ennio-Sr |
---|---|
Тема | Re: Display of text fields |
Дата | |
Msg-id | 20040910175501.GA9535@deby.ei.hnet обсуждение исходный текст |
Ответ на | Re: Display of text fields (Stephan Szabo <sszabo@megazone.bigpanda.com>) |
Список | pgsql-general |
* Stephan Szabo <sszabo@megazone.bigpanda.com> [100904, 10:39]: > On Fri, 10 Sep 2004, Ennio-Sr wrote: > > > > * Stephan Szabo <sszabo@megazone.bigpanda.com> [100904, 07:10]: > > > > > On Fri, 10 Sep 2004, Ennio-Sr wrote: > > > > > [ big cut ] > > > > > Well, I'd expect that for large tables the outer join type solution would > tend to be faster than joining every row to every other row and then using > a unique step (probably after a sort) to basically remove the ones you > don't want. If you try different solutions, you can use EXPLAIN ANALYZE to > compare query plans. Please forget my previous message: I've just finished trying your 'COALESCE' solution (prior to studying it ;) ) and it seems to work greatly! --------- SELECT t0.a, t0.b, t0.c, COALESCE(t1.d, ' ') as note from foo t0 left OUTER JOIN foo_d t1 on (t0.has_d = 'Y' AND t0.a=t1.a); # the result is: a | b | c | note ---+------+--------+---------------------------------- 1 | one | number | is the first natural 2 | two | number | follows 1 in the seq of natural 3 | tree | name | there are various qualities of - 4 | blue | color | 5 | john | person | (5 rows) ^^^ --------- Perfect, I would say :-) Thank you again so much indeed, Stephan. Ennio. -- [Perche' usare Win$ozz (dico io) se ..."anche uno sciocco sa farlo. \\?// Fa' qualche cosa di cui non sei capace!" (diceva Henry Miller) ] (°|°) [Why to use Win$ozz (I say) if ... "even a fool can do that. )=( Do something you aren't good at!" (used to say Henry Miller) ]
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