Received: from localhost (unknown [200.46.204.183])
	by mail.postgresql.org (Postfix) with ESMTP id 22473634E71;
	Thu,  2 Apr 2009 15:19:55 -0300 (ADT)
Received: from mail.postgresql.org ([200.46.204.86])
	by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024)
	with ESMTP id 99682-03-7; Thu,  2 Apr 2009 15:19:52 -0300 (ADT)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from exprod7og105.obsmtp.com (exprod7og105.obsmtp.com [64.18.2.163])
	by mail.postgresql.org (Postfix) with SMTP id 81844635275;
	Thu,  2 Apr 2009 15:19:51 -0300 (ADT)
Received: from source ([209.85.219.169]) by exprod7ob105.postini.com
	([64.18.6.12]) with SMTP
	ID DSNKSdUBxcitXcQfdQAdIs7a3SAwZijUlBof@postini.com;
	Thu, 02 Apr 2009 11:19:51 PDT
Received: by ewy17 with SMTP id 17so649055ewy.28
	for <multiple recipients>; Thu, 02 Apr 2009 11:19:49 -0700 (PDT)
Received: by 10.216.21.194 with SMTP id r44mr149415wer.80.1238696388994;
	Thu, 02 Apr 2009 11:19:48 -0700 (PDT)
Received: from ?80.223.212.7? (dsl-hkibrasgw2-fed4df00-7.dhcp.inet.fi
	[80.223.212.7])
	by mx.google.com with ESMTPS id 10sm1869944eyd.3.2009.04.02.11.19.47
	(version=TLSv1/SSLv3 cipher=RC4-MD5);
	Thu, 02 Apr 2009 11:19:48 -0700 (PDT)
Message-ID: <49D501C2.8060208@enterprisedb.com>
Date: Thu, 02 Apr 2009 21:19:46 +0300
From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
Organization: EnterpriseDB
User-Agent: Mozilla-Thunderbird 2.0.0.19 (X11/20090103)
MIME-Version: 1.0
To: Josh Berkus <josh@agliodbs.com>
CC: "David E. Wheeler" <david@kineticode.com>, lembark@wrkhors.com,
	pgsql-hackers@postgresql.org, pgsql-www@postgresql.org
Subject: Re: [HACKERS] Mentors needed urgently for SoC & PostgreSQL
	Student Internships
References: <49CA7A4D.8040206@agliodbs.com>
	<86CCDB96-2919-4437-952C-43DE4F125EC1@kineticode.com>
	<49D4C9B0.1060309@wrkhors.com>
	<5BAA6B5F-67DB-499B-ACB7-ABA1AC52976D@kineticode.com>
	<49D4FB25.8060400@agliodbs.com>
In-Reply-To: <49D4FB25.8060400@agliodbs.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Archive-Number: 200904/4
X-Sequence-Number: 16871

Josh Berkus wrote:
> On 4/2/09 8:48 AM, David E. Wheeler wrote:
>> On Apr 2, 2009, at 7:20 AM, Steven Lembark wrote:
>>
>>>>> Note that since the Internships are not required to be project code,
>>>>> we can also take student projects to contribute to our WWW
>>>>> infrastructure and other areas the project needs some work.
>>>
>>> Would introducing a Duration (i.e., time-series
>>> a'la Date, et al)) data type be considered useful?
> 
> Jeff Davis has already done a lot of this work; it's on pgFOundry 
> somewhere.

The data type itself is quite trivial. It's all the operators that are 
more difficult to implement, and also immensely useful. That part is 
still incomplete. I'd recommend a book called Temporal Data and the 
Relational Model by C.J. Date, Hugh Darwen and Nikos Lorentzos for 
anyone interested in this topic. That book gives a guideline on how the 
data type and operators should behave.

I'd love to see that implemented. I volunteer to mentor if someone wants 
to tackle it.

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com