How to partition a non-partitioned table

  You can partition a non-partitioned table three different ways:

A) export/import method

B) Insert with a subquery method

C) Partition exchange method

Either of these 3 methods will create a partitioned table from an existing
non-partitioned table.
You can partition a non-partitioned table three different ways:

A) export/import method

B) Insert with a subquery method

C) Partition exchange method

Either of these 3 methods will create a partitioned table from an existing
non-partitioned table.

A. Export/import method
--------------------

1) Export your table:

exp usr/pswd tables=numbers file=exp.dmp

2) Drop the table:

drop table numbers;

3) Recreate the table with partitions:

create table numbers (qty number(3), name varchar2(15))
partition by range (qty)
(partition p1 values less than (501),
partition p2 values less than (maxvalue));

4) Import the table with ignore=y:

imp usr/pswd file=exp.dmp ignore=y

The ignore=y causes the import to skip the table creation and
continues to load all rows.


B. Insert with a subquery method
-----------------------------

1) Create a partitioned table:

create table partbl (qty number(3), name varchar2(15))
partition by range (qty)
(partition p1 values less than (501),
partition p2 values less than (maxvalue));

2) Insert into the partitioned table with a subquery from the
non-partitioned table:

insert into partbl (qty, name)
select * from origtbl;

3) If you want the partitioned table to have the same name as the
original table, then drop the original table and rename the
new table:

drop table origtbl;
alter table partbl rename to origtbl;

C. Partition Exchange method
-------------------------

ALTER TABLE EXCHANGE PARTITION can be used to convert a partition (or
subpartition) into a non-partitioned table and a non-partitioned table into a
partition (or subpartition) of a partitioned table by exchanging their data
and index segments.

1) Create table dummy_t as select with the required partitions

2) Alter table EXCHANGE partition <partition_name>
with <non_partition_table_name>;


Example
-------

SQL> CREATE TABLE p_emp
2 (sal NUMBER(7,2))
3 PARTITION BY RANGE(sal)
4 (partition emp_p1 VALUES LESS THAN (2000),
5 partition emp_p2 VALUES LESS THAN (4000));
Table created.


SQL> SELECT * FROM emp;
EMPNO ENAME JOB MGR HIREDATE SAL
--------- ---------- --------- --------- --------- ---------
7369 SMITH CLERK 7902 17-DEC-80 800
7499 ALLEN SALESMAN 7698 20-FEB-81 1600
7521 WARD SALESMAN 7698 22-FEB-81 1250
7566 JONES MANAGER 7839 02-APR-81 2975
7654 MARTIN SALESMAN 7698 28-SEP-81 1250
7698 BLAKE MANAGER 7839 01-MAY-81 2850
7782 CLARK MANAGER 7839 09-JUN-81 2450
7788 SCOTT ANALYST 7566 19-APR-87 3000
7839 KING PRESIDENT 17-NOV-81 5000
7844 TURNER SALESMAN 7698 08-SEP-81 1500
7876 ADAMS CLERK 7788 23-MAY-87 1100
7900 JAMES CLERK 7698 03-DEC-81 950
7902 FORD ANALYST 7566 03-DEC-81 3000
7934 MILLER CLERK 7782 23-JAN-82 1300
14 rows selected.

SQL> CREATE TABLE dummy_y as SELECT sal
FROM emp WHERE sal<2000;
Table created.

SQL> CREATE TABLE dummy_z as SELECT sal FROM emp WHERE sal
BETWEEN 2000 AND 3999;
Table created.

SQL> alter table p_emp exchange partition emp_p1
with table dummy_y;
Table altered.

SQL> alter table p_emp exchange partition emp_p2
with table dummy_z;
Table altered.