Just noticed a rather interesting little DU glitch

[Oeditpus Rex]

Apparently, if you post something in a thread that then gets kicked to another forum and someone replies to your post in its new location, the reply doesn't show up in "My DU." :shrug:



I wonder if the U Creatures are behind this. :scared:

[CreekDog]

1. What's a U creature? Is it a replicant?

:shrug:

[Jamastiene]

15. We all had UU between every post and

a line of UUUUUUUUUUUU...all the way across the top of the forums yesterday. They seem to have quietly disappeared...for now. :tinfoilhat:

[VenusRising]

2. I noticed that last week.

It's a long round about way to get to the thread, but if you click on the original thread title in my DU, it takes you to the link to the new thread location. Click on that and that should take you to the thread. Find your own message and the reply.

:crazy:

:hi:

[billyskank]

3. And if you click (from My DU) on your post in the thread that got moved

you get the "missing topic" error screen, the same one you get when the thread has been deleted.

[flvegan]

4. Also, if a thread is on the DU home page, and it gets moved to the Lounge

it stays on the homepage, but has The Lounge listed as the forum.

[billyskank]

5. It means they've denormalized the hell out of their database.

Only a database programmer will know what I'm on about here, but it's something you do to your database to make it run faster.

When you denormalize the database you can run into data integrity problems, which is what you guys are noticing here.

[LynzM]

6. question for ya, Billy...

Can you explain that in a way that I could understand? I've only got MSAccess experience, for build (and a proprietary one you'll never have heard of, where I don't really get to do the build from scratch.)

I want to understand what you mean :)

[billyskank]

7. When you denormalize, you remove the need for a join.

If tables A and B had a one-to-one relationship between them, you might possibly want to improve performance by copying some columns from B into A so that you can select all the data you need without the join. That's the essence of it.

The 'perfect' state for a database is called Third Normal Form, where all columns in a table depend only on its primary key and nothing else. Columns that depend on other 'foreign' keys (i.e. in other tables) have to be referenced by a table join.

When you denormalize, you copy some of the columns from the foreign table that is referenced by the foreign key. This improves performance, but now you have duplicated data that can go out of sync if you are not careful. We have this problem a lot where I work. Our database is an absolute mess, has no integrity constraints and it is riddled with data integrity problems.

No production database will run in third normal form. They simply won't perform. In the real world, it is always necessary to denormalize a little bit in order that certain queries run fast enough to be useable. A good way of approaching database design is to start with third normal form and then denormalize as necessary. But when you denormalize, you should take care to ensure that when the data is updated in its home table, the denormalized data is updated to match it. If you don't, then you end up with inconsistencies like the guys are talking about here.

Does that make any sense? I'm not sure if I am any good at explaining this.

:hi:

[hisownpetard]

8. When you're demoralized, it removes the need for a joint??

[LynzM]

10. That was excellent, thank you.

That all makes sense, and basically explains what I thought more intuitively - that the location was "saved" somewhere instead of only being in one place, and that "saved" location didn't get updated when the other location did. :)

What is it about 3rd normal form that keeps a db from performing in that way? Just the time to sort through the joins in the SQL?

Thanks for taking the time to write that all out for me! What kind of DBs do you admin? I'm currently working in Clinical Data stuff...

[Oeditpus Rex]

12. Quit geekjackin' my thread!

Ya geekjackers. x(

[Jamastiene]

16. ...

:spray:

[LynzM]

19. Bwahahahahaha.....

:rofl:


:loveya:

[billyskank]

14. You're so welcome.

It's just all the table joins that make the database too slow to be useable. Maybe a small system will run okay, but most applications will require a few performance tweaks to get them running at an acceptable speed.

I'm a programmer not an admin, I work on Oracle databases. My current job is in horse racing, I work for the administrators of UK and Ireland horse racing. As you'd expect, they have a massive database full of horses, jockeys, races, performances, owners, etc.

:hi:

[LynzM]

18. Oh wow.

Neato :) We used Oracle Clinical for one of our major clients, so I'm familiar with it in that context, anyway. Would be interesting to see how different it is when you get it out of the clinical setting.

</geekjack> :rofl:

[Fredda Weinberg]

11. Denormalization is used for data warehousing and analysis

There's no time for look up tables ... so you can have production (yes, I've run 3rd normal, no further thank you) and massive time sensitive data in denormalized form.

[Jamastiene]

17. Well, I don't know jack shit about databases, except how to query...

but I kind of followed what you were saying. :think:

[HiFructosePronSyrup]

9. U creatures?

Would that be umber hulks? Or equines such as horses, ponies, warhorses and unicorns?

[Orsino]

13. UN Secretary-Generals. n/t