Add New partition

Question

Hello,
Oracle 11.2.0.1
Windows
I am having one partitioned IOT something like this :
create table my_table (
col1 number(10) not null,
col2 varchar2(7) not null,
col3 varchar2(20) not null,
col4 varchar2(20) not null,
col5 varchar2(20) not null,
col6 date not null,
col7 number(4) not null,
col8 varchar2(1) not null,
col9 varchar2(1) not null,
primary key(col1,col2,col3,col4,col5,col6,col7,col8,col9)
organization index
partition by range (col3,col4,col5)
(partition p1 values less than('A%','A%','A%'),
partition p2 values less than('B%','B%','B%'),
partition p3 values less than('C%','C%','C%'),
PARTITION p27 VALUES LESS THAN (MAXVALUE,MAXVALUE,MAXVALUE))
Now, I want to add new range partition on column col7. There is an index exist on col7 too, but since table is carrying around 200 million rows, only having index is not looking good, so I thought to add similar type of partition on col7. In col7 there are range value between 2000 to 2010 only.
Kindly tell me how do I proceed to add new partition on another column of existing partitioned IOT please.
Thanks.

Answer 1

i thought that I am having the data of all student_name, father_name and mother_name whose name starts from A in partition p2 (because B is less than A) and like wise upto Z. Am I clear this ? I mean, if I says a student whose name is Boby John (partition p3), father name Robert (partition p19) and mother name Lilly (partition p13) ?A row can be in exactly one partition. It can't be in three different partitions. If you want to create 26*26*26 partitions, then you could have a separate partition for each possible combination. If you want just 26 partitions, you would realistically only want to partition by one column (presumably student_name).
select * from my_table where student_name like '%Boby%' and father_name like '%Robert%' and mother_name like '%Lilly%' and passing_year=2001. This would prevent Oracle from doing any sort of partition pruning since you're looking for a string anywhere within the name. You'd be better off not partitioning the table at all if you want to run this sort of query. You'd be much better off using Oracle Text and turning your LIKE conditions into CONTAINS conditions.
So, I think oracle is using 3 partitions i.e. P3 for Boby, P19 for Robert and P13 for Lilly. Upto this query is running fine and very good, no issue of slowness, but when ever query gets year=something other than 2001, it takes time. So, I thought I should have partitions on passing_year column too.No. A row exists in exactly 1 partition. Oracle has to scan all 26 partitions to satisfy this query. It would be more efficient not to partition the table at all. Even if you created 26*26*26*10 partitions, Oracle would still have to scan 26*26*26 partitions since passing_year is the only predicate on which you could do partition pruning. But that is unlikely to be useful-- you'd almost certainly be better off with no partitioning.
Justin