Re: Normalization question

Erland,

I don't know the extent of your colloquial English knowledge, but I have to say that I go bananas over questions like this, and they often drive me bananas.

Steve

Erland Sommarskog wrote:

> Steve Kass <skass_at_drew.edu> writes:
> > The example here in fact is very similar to some popular schemes
> >for image compression. Recording just the changes is a lossless
> >compression scheme. And the parallel goes a bit further, in that
> >both for a .gif image and for the table in the compact form Erland
> >suggested (no End_dt), there are similar disadvantages. If a row of
> >the table is corrupted or lost, a potentially large amount of information
> >can become irretrievable. And without corruption, the information itself
> >becomes harder to retrieve (to wit Erland's use of both
> >compressed and uncompressed tables, depending on the situation).
>
> That reminds me of a quite horrendeous war story. We had a table in our
> systems for a certain type of objects call them bananas. Then we introduced
> a somewhat different slant of banaas, which result in the three tables:
>
> bananas - the virtual subtable with all bananas
> yellow_bananas - the old kind of bananas we always had supported.
> red_bananas - the new kind of bananas.
>
> The yellow_bananas and red_bananas tables are very different. 95% of
> all bananas are in the yellow_bananas tables, and at sites that don't
> deal with red_bananas 100% of all bananas are in the yellow_bananas
> table. Furthermore, the red_bananas table only has the columns specific
> to the red bananas, where as yellow_bananas duplicates many of the
> columns in the main table (as some of the column in the bananas_tree
> table) of legacy reasons.
>
> What happened at one site was that the bananas table became corrupt.
> This site does not have red bananas, so we were able to fully reconstruct
> the bananas table from yellow_bananas table. And I have to say it scared
> me. Sure, at this incident it was good, but since the bananas tables
> are transaction-intensive, that means that our system is doing a lot of
> extra work.
>
> Quite recently, I have arrived at the conclusion that introducing the
> supertable was a mistake. After all, we have already squeezed in blue
> bananas in the yellow_bananas table, and they are actually even stranger
> creatures than the red ones. So the idea now is to go back to the
> original single-table concept.
>
> --
> Erland Sommarskog, Stockholm, sommar_at_algonet.se
Received on Thu Jun 27 2002 - 21:17:03 CEST