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From:Rudy Lippan Date:January 29 2010 11:12pm
Subject:Re: 50 things to know before migrating from Oracle to MySQL
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On 01/29/2010 02:57 PM, Chris W wrote:

> Hardcore stupid if you ask me.  I suppose it is "possible" to have a
> valid reason (can't imagine what it might be) for using more than 61

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.

> joins.  But I would be willing to bet that 99.99% of the time if you get
> even close to that many joins you have a very poorly designed database. 
> I would also bet that 80% of the people who are actually writing queries
> with that many joins don't have a solid grasp of the fundamental
> principles of relational database design.

I suspect otherwise. In my experience, most of the time when someone
does not understand relational databases, there is a tendency towards
fewer tables; and, in the few cases where I have seen too many tables,
the joins were more likely to be done in the application code than in
the database... Fun Times there....

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. 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.


-r
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