From: Oliveiros d'Azevedo Cristina <oliveiros.cristina@marktest.pt>
To: Louis-David Mitterrand <vindex+lists-pgsql-sql@apartia.org>
To: pgsql-sql@postgresql.org
Subject: Re: "compressing" consecutive values into one
Date: Tue, 23 Nov 2010 15:31:59 -0000
Message-ID: <5678C0F3BD5E48F587D8065C9C38BAA9@marktestcr.marktest.pt> (raw)
References: <20101123151918.GA22094@apartia.fr>
Salut, Louis-David,
Can you please state the columns belonging to price table
and give a concrete example?
Say, data before and data after you want to do?
Thank you
A bien-tôt,
Oliveiros
----- Original Message -----
From: "Louis-David Mitterrand" <vindex+lists-pgsql-sql@apartia.org>
To: <pgsql-sql@postgresql.org>
Sent: Tuesday, November 23, 2010 3:19 PM
Subject: [SQL] "compressing" consecutive values into one
> Hi,
>
> On time series price data I'm trying to remove consecutive identical
> prices and keep only the latest. I tried:
>
> delete from price where id_price in (select t.id_price2 from (select
> first_value(p.id_price) over w as id_price1,
> nth_value(p.id_price, 2) over w as id_price2,
> first_value(p.price) over w as price1,
> nth_value(p.price,2) over w as price2
> from price p
> window w as (partition by p.id_rate,p.id_cabin_category,p.id_cruise
> order by p.id_price desc rows between unbounded preceding and
> unbounded following)) as t where price1 = price2);
>
> and it mostly works but I have to do several runs to completely
> eliminate identical consecutive prices.
>
> Is there a better, one-pass, way?
>
> Thanks,
>
> --
> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
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To: pgsql-sql@postgresql.org
Cc: oliveiros.cristina@marktest.pt, vindex+lists-pgsql-sql@apartia.org
Subject: Re: "compressing" consecutive values into one
In-Reply-To: <5678C0F3BD5E48F587D8065C9C38BAA9@marktestcr.marktest.pt>
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