Re: webmail user mailbox schema design?
Date: Fri, 1 May 2009 10:51:19 -0700 (PDT)
Message-ID: <a699a382-84dc-41b9-ae66-a35041d7d8e8_at_j9g2000prh.googlegroups.com>
On May 1, 9:37 am, ddf <orat..._at_msn.com> wrote:
> Partitioning the MESSAGES table on user_id could provide speed and
> manageability by segregating each users messages to a single
> partition; partition pruning would eliminate visits to unrelated
> partitions effectively reducing the data set to a fraction of the
> total number of messages stored.
I struggle to understand a single advantage of partitioning. Well, you listed one advantage -- easy deletion. However, since when deletion became a determining factor in database design?
Let me list disadvantages.
lies.
create table trans (
trans_id number, trans_dt date, product_code number, store_id number, trans_amount number(12,2)
)
partition by range (trans_dt)
(
partition y05q1 values less than (to_date('04/01/2005','mm/dd/ yyyy')) tablespace y05q1,
partition y05q2 values less than (to_date('07/01/2005','mm/dd/ yyyy')) tablespace y05q2,
partition y05q3 values less than (to_date('10/01/2005','mm/dd/ yyyy')) tablespace y05q3,
partition y05q4 values less than (to_date('01/01/2006','mm/dd/ yyyy')) tablespace y05q4,
partition pmax values less than (maxvalue) tablespace users )
And I'm not even going into kitchen sink of subpartitions... Received on Fri May 01 2009 - 19:51:19 CEST