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

Re: how to get a number of seconds in some interval ?

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Achilleas Mantzios <achill(at)matrix(dot)gatewaynet(dot)com>
Cc: Julius Tuskenis <julius(at)nsoft(dot)lt>, pgsql-admin(at)postgresql(dot)org
Subject: Re: how to get a number of seconds in some interval ?
Date: 2008-05-12 15:09:11
Message-ID: 20080.1210604951@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-admin
Achilleas Mantzios <achill(at)matrix(dot)gatewaynet(dot)com> writes:
>  Monday 12 May 2008 17:32:39 / Julius Tuskenis :
>> do you know why division of intervals was not implemented? As I see it - 
>> there should be an easy way to do so. '1 hour 30 minutes' / '1 hour' = 
>> 1.5 .... Seems straight forward...
>> 
> No idea why. However as you pose it,it makes sense.

No, it doesn't really, because intervals contain multiple components.
What would you define as the result of
	'1 month 1 hour' / '1 day'
bearing in mind that the number of days per month is not fixed, and
neither is the number of hours per day?

You can derive a number if you're willing to make arbitrary assumptions
about the relationships of the different units (as indeed extract(epoch)
does), but hard-wiring such assumptions into a basic arithmetic operator
doesn't seem like a good idea to me.

			regards, tom lane

In response to

Responses

pgsql-admin by date

Next:From: Travis SmithDate: 2008-05-12 16:41:04
Subject: Postgres Cluster on Solaris
Previous:From: Achilleas MantziosDate: 2008-05-12 15:01:34
Subject: Re: how to get a number of seconds in some interval ?

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