Re: generate_series from now to infinity...
От | Dickson S. Guedes |
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Тема | Re: generate_series from now to infinity... |
Дата | |
Msg-id | 1242582655.18964.33.camel@guedes-laptop обсуждение исходный текст |
Ответ на | Re: generate_series from now to infinity... (hubert depesz lubaczewski <depesz@depesz.com>) |
Список | pgsql-hackers |
Em Dom, 2009-05-17 às 19:22 +0200, hubert depesz lubaczewski escreveu: > it doesn't for this query: > > SELECT i from generate_series(now(), CAST('infinity'::date AS > timestamp), interval '1 hour') as x (i) limit 3; > > which (as far as i understand it) should be the same. > > why is it not limiting generate_series in the second example? is it > intentional? The EXPLAIN output differ between both. postgres=# EXPLAIN SELECT generate_series(now(), CAST('infinity'::date AS timestamp), interval '1 hour') limit 3; QUERY PLAN ------------------------------------------------Limit (cost=0.00..0.02 rows=1 width=0) -> Result (cost=0.00..0.02 rows=1width=0) postgres=# explain SELECT i from generate_series(now(), CAST('infinity'::date AS timestamp), interval '1 hour') as x (i) limit 3; QUERY PLAN --------------------------------------------------------------------------------Limit (cost=0.00..0.05 rows=3 width=8) -> Function Scan on generate_series x (cost=0.00..17.50 rows=1000 width=8)
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