How To optimize a database ?

[Ivan Smahin]

Hello Thierry,

Wednesday, December 7, 2005, 8:38:17 AM, you wrote:


TN> Question: is it preferable to have several tables with few columns or
TN> a single table with many columns?
TN> That is not maybe impossible!

There is no particular answer.
Both  issues  could  be  used  - depends on your task. If you perform
joins  very  often,  probably, you prefer to make some denormalization.
(All data in the single table.)
(But note - you could get some duplicated rows - for each D values.)

On  the  other  hand, the nature of some databases is to store data as
row   -   field   by   field.  So  it  could  be significant slow down
reading/writing such a denormalized table.

I    would   say  -  there is some limit exists. If you have only few
columns in the second table and it is linked as 1::1 to the first - you'd
better make a single table.


BTW, you need some good book described this stuff:
Normalizing, normal forms and so on...

-- 
Best regards,
 Ivan                            mailto:IvanSmahin at public.kherson.ua