Apress.Expert.Oracle.Database.Architecture.9i.and.10g.Programming.Techniques.and.Solutions.Sep.2005

CHAPTER 13 ■ PARTITIONING 591
ops$tkyte@ORA10G> CREATE TABLE partitioned
2 ( timestamp date,
3 id int
4 )
5 PARTITION BY RANGE (timestamp)
6 (
7 PARTITION part_1 VALUES LESS THAN
8 ( to_date('01-jan-2000','dd-mon-yyyy') ) ,
9 PARTITION part_2 VALUES LESS THAN
10 ( to_date('01-jan-2001','dd-mon-yyyy') )
11 )
12 /
Table created.
ops$tkyte@ORA10G> create index partitioned_index
2 on partitioned(id)
3 GLOBAL
4 partition by range(id)
5 (
6 partition part_1 values less than(1000),
7 partition part_2 values less than (MAXVALUE)
8 )
9 /
Index created.
Note the use of MAXVALUE in this index. MAXVALUE can be used in any range partitioned table
as well as in the index. It represents an “infinite upper bound” on the range. In our examples
so far, we’ve used hard upper bounds on the ranges (values less than ). However,
a global index has a requirement that the highest partition (the last partition) must have a partition
bound whose value is MAXVALUE. This ensures that all rows in the underlying table can be
placed in the index.
Now, completing this example, we’ll add our primary key to the table:
ops$tkyte@ORA10G> alter table partitioned add constraint
2 partitioned_pk
3 primary key(id)
4 /
Table altered.
It is not evident from this code that Oracle is using the index we created to enforce the
primary key (it is to me because I know that Oracle is using it), so we can prove it by simply
trying to drop that index:
ops$tkyte@ORA10G> drop index partitioned_index;
drop index partitioned_index
*
ERROR at line 1:
ORA-02429: cannot drop index used for enforcement of unique/primary key