Re: Speed question - new view using preview view components
От | Daniel Staal |
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Тема | Re: Speed question - new view using preview view components |
Дата | |
Msg-id | A665C78CF8F4E47CEFEA2044@mac-pro.magehandbook.com обсуждение исходный текст |
Ответ на | Speed question - new view using preview view components (richard terry <rterry@pacific.net.au>) |
Список | pgsql-novice |
--As of March 21, 2010 12:23:19 PM +1100, richard terry is alleged to have said: > I wondered if when creating a new view from multiple tables, and then > also joining to some fields of an existing view, if one pays much of a > speed penalty when the data is retrieved, as opposed to just completely > using all tables. --As for the rest, it is mine. First off, to help you answer your question (and others like it in the future) yourself: <http://www.postgresql.org/docs/8.4/interactive/sql-explain.html> Which I believe will tell you that there is no difference as far as Postgres is concerned. It will see the two selects (assuming they actually have the same structure) exactly the same: The view only makes it easier to write the first. (At least in this use.) Daniel T. Staal --------------------------------------------------------------- This email copyright the author. Unless otherwise noted, you are expressly allowed to retransmit, quote, or otherwise use the contents for non-commercial purposes. This copyright will expire 5 years after the author's death, or in 30 years, whichever is longer, unless such a period is in excess of local copyright law. ---------------------------------------------------------------
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