Re: partitionning join table and normalization

chmanu_at_gmail.com wrote:
> Hello,
>
> I'm working on a database which contains a big table TD (10 millions
> lines) with many columns (180)
>
> I wonder if the performance won t be better if i normalize some
> columns (about 20).
>
> So this is the new table NORM_FIELD :
> ID_DATA (ID reference from original table)
> FIELD_ID
> FIELD_DATA
> + 3 - 4 fields about updating (date, user, ...)
>
> TD is partitionning case 2 columns.
> Is it possible to partitionning NORM_FIELD which the same critery of
> TD ?
> Even ifnot, what the better solution between :
> - copy data of partitioning field in NORM_FIELD to store in the same
> partition (and have this critery for the join condition)
> - create a new partitioning critery for NORM_FIELD (like the last
> digit for having the best distribution)
>
> I don t want to change the application code, so i will rename my table
> and create a view with this name which will be a join with a another
> view build from this method :
> http://oracle.ittoolbox.com/groups/technical-functional/oracle-db-l/denormalizing-data-898552
>
> Will performance be ok if i do this change ?
> What s about your experience ?
>
> Thanks for answers.
>
> Chmanu
>
> PS : it is possible i've not be clear cause my poor english, in this
> case ask me to explain.

Performance may or may not improve but maintainability and the ability to use it for something other than a data-dumpster will.

10M rows is not a particularly large table. But 180 columns is, in the vast majority of cases, a really bad idea.

-- 
Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington
damorgan_at_x.washington.edu (replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org