[AccessD] RE: Using Dates

Charlotte,

Correct, it would be taken care of in the ETL (Extract, Transform, and 
Load) process for the fact tables.

Robert

At 01:27 PM 2/3/2004 -0800, you wrote:
>I see.  But in that case, you would probably massage the data when it
>went into the data warehouse, wouldn't you?  You would have to in order
>to introduce the surrogate key.  It isn't like this is transactional
>data.
>
>Charlotte
>
>-----Original Message-----
>From: Robert L. Stewart [mailto:rl_stewart at highstream.net]
>Sent: Tuesday, February 03, 2004 11:32 AM
>To: accessd at databaseadvisors.com
>Cc: Charlotte Foust
>Subject: Re: Using Dates
>
>
>Charlotte,
>
>What I think he is saying is that in 99% of the cases, the regular date
>dimension table will work.  In a few cases, where the date may be
>missing
>and you want to get some kind of value for it, you cannot use the date
>itself as the key, thus the surrogate.  The surrogate would be stored in
>
>the fact tables (another data warehousing concept, for those that do not
>
>know about them).  That way when you hit an invalid or null date value,
>the
>date dimension table would be able to handle it in a predefined way.
>
>Robert
>
>At 03:46 AM 2/3/2004 -0600, you wrote:
> >Date: Mon, 2 Feb 2004 12:29:49 -0800
> >From: "Charlotte Foust" <cfoust at infostatsystems.com>
> >Subject: RE: [AccessD] RE: Using Dates
> >To: "Access Developers discussion and problem solving"
> >         <accessd at databaseadvisors.com>
> >Message-ID:
> >
><E61FC1D4B1918244905B113C680BEA8632C448 at infoserver01.infostat.local>
> >Content-Type: text/plain;       charset="us-ascii"
> >
> >I'm not even sure what Ralph is saying there, and it flies in the face
> >of what he does in some of his books, so I have no answer for you,
> >John. Keep in mind, though, that datawarehouses are indexed somewhat
> >differently from transactional databases, so that may be where the
> >confusion is coming in.  If you were using surrogate keys and
> >meaningless values as the PK, the dates in the main records would need
> >to be inserted *from* the date table, and that isn't generally the way
> >the thing is used.
> >
> >Charlotte Foust