Обсуждение: View Vs. Table

Hi,

I have two tables which currently are being aggregated into a third table.
I am proposing eliminating or drastically shortening the 3rd aggregation
table, and instead just using a View.

Which brings me to the question, which is better? Reading from a table or
a view or is there a difference in performance?

From the application's perspective the View is much better as data is
being stored in one place, reducing errors and also storage.
But from the db point of view, is there a bigger performace hit when I
query a view Vs a table or is there no difference.

Thanks,
Radhika



-- 
It is all a matter of perspective. You choose your view by choosing where
to stand.
Larry Wall
---

On Tue, Mar 06, 2007 at 09:32:19 -0500, Radhika Sambamurti <sushi@88thstreet.com> wrote:
> 
> From the application's perspective the View is much better as data is
> being stored in one place, reducing errors and also storage.
> But from the db point of view, is there a bigger performace hit when I
> query a view Vs a table or is there no difference.

In postgres, views are essentially macros and there shouldn't be a big
performance hit for using them over issuing the equivalent query.

It sounds like what you might be asking is comparing views to storing
data in denormallized tables (esentially materialized views). You generally
don't want to go there unless you need to, to get acceptible performance.
(And note that denormallizing data doesn't always get you better performance.)