Re: Do Views execute underlying query everytime ??

From: Amit V Shah <ashah(at)tagaudit(dot)com>
To: "'newz(at)bearfruit(dot)org'" <newz(at)bearfruit(dot)org>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Do Views execute underlying query everytime ??
Date: 2005-06-21 14:49:28
Message-ID: 0C072E7CC947D511AC9600A0CC7341200256CF52@vpn.tagaudit.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

After I sent out this email, I found this article from google

http://jonathangardner.net/PostgreSQL/materialized_views/matviews.html

Looks like we can control as to when the views refresh... I am still kind of
confused, and would appreciate help !!

The create/drop table does sound a solution that can work, but the thing is
I want to get manual intervention out, and besides, my work flow is very
complex so this might not be an option for me :-(

Thanks,
Amit

-----Original Message-----
From: Matthew Nuzum [mailto:mattnuzum(at)gmail(dot)com]
Sent: Tuesday, June 21, 2005 10:45 AM
To: Amit V Shah
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: [PERFORM] Do Views execute underlying query everytime ??

On 6/21/05, Amit V Shah <ashah(at)tagaudit(dot)com> wrote:
> Hi all,
...
> I am thinking of having a solution where I create views for each screen,
> which are just read only.
>
> However, I donot know if the query that creates the view is executed
> everytime I select something from the view. Because if that is the case,
> then I think my queries will again be slow. But if that is the way views
> work, then what would be the point in creating them ..
>
> Any suggestions, helps --

They do get executed every time. I have a similar issue, but my data
does not change very frequently, so instead of using a view, I create
lookup tables to hold the data. So once a day I do something like
this:
drop lookup_table_1;
create table lookup_table_1 as SELECT ...;

In my case, rows are not deleted or updated, so I don't actually do a
"drop table..." I merely add new records to the existing table, but if
your data changes, the drop table technique can be faster than doing a
delete or update.

--
Matthew Nuzum
www.bearfruit.org

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Yves Vindevogel 2005-06-21 14:57:51 Re: Limit clause not using index
Previous Message Richard Huxton 2005-06-21 14:48:39 Re: Do Views execute underlying query everytime ??