Re: Temporal database - no end date
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sat, 20 Jan 2007 17:23:50 GMT
Message-ID: <Gessh.3198$1x.54397_at_ursa-nb00s0.nbnet.nb.ca>
>
>
> Suppose I have 5 things. 4 of them lasted for 1 'day' before they
> break.The other broke on the same 'day' it went out.
>
> What is the mean time to failure?
>
> Sum of 'time quanta' = 4.
> Number of things = 5.
>
> Mean time to failure = 0 time quanta.
>
> Pick any intuitive unit of 'time quanta', and you can construct an
> example where this problem arises.
Date: Sat, 20 Jan 2007 17:23:50 GMT
Message-ID: <Gessh.3198$1x.54397_at_ursa-nb00s0.nbnet.nb.ca>
DBMS_Plumber wrote:
>>Could you show with an example how the loss occurs ? You may be right, but >>let's see.
>
>
> Suppose I have 5 things. 4 of them lasted for 1 'day' before they
> break.The other broke on the same 'day' it went out.
>
> What is the mean time to failure?
>
> Sum of 'time quanta' = 4.
> Number of things = 5.
>
> Mean time to failure = 0 time quanta.
>
> Pick any intuitive unit of 'time quanta', and you can construct an
> example where this problem arises.
By your reasoning, one cannot calculate 'total fertility' unless one assumes children form a continuum. Absurd nonsense. Received on Sat Jan 20 2007 - 18:23:50 CET