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From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: David Jarvis <thangalin@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org, Magnus Hagander <magnus@hagander.net>
Subject: Re: Analysis Function
Date: Sun, 13 Jun 2010 09:02:23 +0300
Message-ID: <4C14746F.9050603@enterprisedb.com> (raw)
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On 11/06/10 23:38, David Jarvis wrote:
> I added an explicit cast in the SQL:
>
>          dateserial(extract(YEAR FROM
> m.taken)::int,'||p_month1||','||p_day1||') d1,
>          dateserial(extract(YEAR FROM
> m.taken)::int,'||p_month2||','||p_day2||') d2
>
> The function now takes three integer parameters; there was no performance
> loss.

We had a little chat about this with Magnus. It's pretty surprising that 
there's no built-in function to do this, we should consider adding one.

We could have a function like:

construct_timestamp(year int4, month int4, date int4, hour int4, minute 
int4, second int4, milliseconds int4, timezone text)

Now that we have named parameter notation, callers can use it to 
conveniently fill in only the fields needed:

SELECT construct_timestamp(year := 1999, month := 10, date := 22);

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



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