List:General Discussion« Previous MessageNext Message »
From:Jigal van Hemert Date:January 30 2010 1:46pm
Subject:Re: 50 things to know before migrating from Oracle to MySQL
View as plain text  
Rudy Lippan wrote:
> How about complex data requirements?  Depending on the resolution of
> your data set, I could see a "simple" person-type object that contained
> name, address, SSN, mother, and birth_info starting to approach the limit.
> 
> Cities change, address changes, names change, and even mothers can
> change. The simple-looking street part of an address can have (at least)
> number, direction, name, suffix, any of which can change.

Okay, so you want to link a person to an address table. I can justify 
that in the case of multiple addresses with a single person. But then 
you build a 'city' table to normalize that. Or no, better make a zip 
code table, link that to the 'city' table.
Wait, streets can change names; a 'street' table too to link. Oh no! 
sometimes streets are split. So an address is a 'property' (a piece of 
ground), linked to a street, street linked to zip code, zip code linked 
to city. Damn (sorry), a 'property' can be divided... Oh my...

Ever thought about updating a table by renaming a street? Or by 
selecting a group of street-number combinations and rename them?

> The real art is trying to balance the need of simplicity and ease of
> understanding with the need for flexibility, and that has nothing to do
> with relational theory. 

In real life the balance tends to go to unnecessary flexibility 
resulting in systems which are simply too heavy for the actual needs.

 > Complex datasets are, by their nature, complex,
> and can only be simplified so much. You try to hide the complexity, you
> shift it, you move-it, you send it to its room, you pretend it is not
> there. And yet it still pops up at the most inopportune times and has to
> be dealt with.

And still, in a lot of cases the complex datasets are even made more 
complex by normalization, trying to be ultimately flexible and creating 
a solution for problems which simply don't exist.

In almost all cases a simple solution will be the best.

Regards,

Jigal van Hemert.
Thread
50 things to know before migrating from Oracle to MySQLchanguno 28 Jan
  • Re: 50 things to know before migrating from Oracle to MySQLJohan De Meersman28 Jan
  • Re: 50 things to know before migrating from Oracle to MySQLShawn Green28 Jan
    • Re: 50 things to know before migrating from Oracle to MySQLpaul rivers28 Jan
  • Re: 50 things to know before migrating from Oracle to MySQLJohn Meyer28 Jan
    • RE: 50 things to know before migrating from Oracle to MySQLDaevid Vincent28 Jan
  • Re: 50 things to know before migrating from Oracle to MySQLCarl28 Jan
    • Re: 50 things to know before migrating from Oracle to MySQLJohnny Withers29 Jan
  • Re: 50 things to know before migrating from Oracle to MySQLfsb29 Jan
    • Re: 50 things to know before migrating from Oracle to MySQLChris W29 Jan
      • Re: 50 things to know before migrating from Oracle to MySQLmos29 Jan
        • Re: 50 things to know before migrating from Oracle to MySQLTom Worster1 Feb
          • Re: 50 things to know before migrating from Oracle to MySQLCarl1 Feb
            • Re: 50 things to know before migrating from Oracle to MySQLMichael Dykman1 Feb
          • Re: 50 things to know before migrating from Oracle to MySQLMartijn Tonies1 Feb
      • Re: 50 things to know before migrating from Oracle to MySQLRudy Lippan30 Jan
        • Re: 50 things to know before migrating from Oracle to MySQLShawn Green30 Jan
          • Re: 50 things to know before migrating from Oracle to MySQLRudy Lippan31 Jan
        • Re: 50 things to know before migrating from Oracle to MySQLJigal van Hemert30 Jan
    • Re: 50 things to know before migrating from Oracle to MySQLMartijn Tonies29 Jan
      • Re: 50 things to know before migrating from Oracle to MySQLJørn Dahl-Stamnes29 Jan
      • Re: 50 things to know before migrating from Oracle to MySQLJigal van Hemert30 Jan
    • Re: 50 things to know before migrating from Oracle to MySQLMartijn Tonies1 Feb
      • Re: 50 things to know before migrating from Oracle to MySQLJigal van Hemert1 Feb
    • Re: 50 things to know before migrating from Oracle to MySQLMartijn Tonies1 Feb
  • Re: 50 things to know before migrating from Oracle to MySQLJohn G. Heim29 Jan
  • Re: 50 things to know before migrating from Oracle to MySQLMartijn Tonies29 Jan