Skip site navigation (1) Skip section navigation (2)

Re: Perfomance of views

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Svenne Krap <svenne(at)krap(dot)dk>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Perfomance of views
Date: 2005-10-27 14:38:02
Message-ID: 18899.1130423882@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-performance
Svenne Krap <svenne(at)krap(dot)dk> writes:
> The ways I have considered was :
> 1) write a big query in hand (not preferred as it gets hard to manage)
> 2) write layers of views (still not prefered as I still have to remember 
> to put on the right conditions everywhere)
> 3) write layers of sql-functions (returning the right sets of rows from 
> the underlying tables) - which I prefer from a development angel .. it 
> gets very clean and I cant forget a parameter anywhere.

#1 and #2 should behave pretty similarly, assuming that the "one big
query" would have been structured the same way as the nest of views is.
#3 unfortunately will pretty much suck, because there's no chance for
cross-level optimization.

There's been some discussion of inline-expanding SQL functions that
return sets when they are called in FROM, which would make a SQL
function that contains just a SELECT effectively equivalent to a view
as far as the planner's powers of optimization go.  No one's tried to
make it happen yet though.

			regards, tom lane

In response to

Responses

pgsql-performance by date

Next:From: Svenne KrapDate: 2005-10-27 15:10:29
Subject: Re: Perfomance of views
Previous:From: Edward Di Geronimo Jr.Date: 2005-10-27 14:35:41
Subject: Re: Performance issues with custom functions

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group