Problem in Partitioning a Table

Question

Hi,
We have a table which we want to partition by the modulo of the week of the year (obtained from CREATE_DATE column) divided by 4. So this table should have four partitions 0, 1, 2 and 3.
For example a record inserted in the table on 25th January 2007 i.e. the fourth week of the year should reside in the partition 0.
We tried creating the table as follows: -
create table test
id number not null,
create_date date not null,
web_order_number varchar2(32)
partition by list (mod(to_number(to_char(create_date,'WW')),4))
partition olss_session_wrk_0 values (0),
partition olss_session_wrk_1 values (1),
partition olss_session_wrk_2 values (2),
partition olss_session_wrk_3 values (3)
tablespace data_ts;
But we are getting the following error : -
ORA-00907: missing right parenthesis
Are we missing something here ? Is there any other way of achieving our requirement ? Any help would be greatly appreciated.
Regards,
Suman

Answer 1

You do realise that using that partitioning criteria will not make any existing SQLs faster?
When parsing a SQL that uses the CREATE_DATE as a predicate, the CBO will have no idea in which partition, rows for that CREATE_DATE reside.
So much for performance gains then.
Now usually the other primary reason for partitioning is data management. Like aging out all the rows for a specific period to archives or something along those lines.
Oh, but wait.. all the years worth of CREATE_DATE rows will reside in one of only 4 partitions. Thus no way to perform a partition exchange to move data in/out, no way to age data out of a sliding window by dropping or truncating a partition.
But hey, at least you have your data partitions into 4 neat and kewl partitions. Even if it is pretty much useless ito performance and data management.