Re: Logically model never possible real world or my forever imperfect business?

From: Mike Sherrill <MSherrill_at_compuserve.com>
Date: Thu, 13 Mar 2003 13:03:37 -0500
Message-ID: <10h17vkuqf58em61b6jdfvi131vlq77a4s@4ax.com>

On 6 Mar 2003 09:58:58 -0800, olegjay_at_yahoo.com (OlegJay) wrote:

[snip]

>I think I should model my database as having two entities
>and its in 3rd normal form.

3NF is a characteristic of a table, not a database.

>However my data source for parcels and owners comes from type written
>notes
>and ownername could be coming to me mispelled. The same person may
>own
>several parcels and each time his name could be mispelled differently.
> Furthermore,
>even after this database is constructed I will have no source of
>cleaning
>ownernames up, so as far as the database knows it can not assume one
>'JOHN SMITH'
>is the same as another or if its the same as 'JON SMITH'.

It seems to me you're not concerned about owners; you're concerned about what a source says about ownership. Think about the logical difference between these (rough) sentences.

John Smith owns parcel 32.
Title 'A100', dated '1901-12-31', says John Smith owns parcel 32. Tax record 'B100', dated '1902-04-15' says Jon Smyth owns parcel 32.

-- 
Mike Sherrill
Information Management Systems

Received on Thu Mar 13 2003 - 12:03:37 CST