Hash partitioning

Hash partitioning is a partitioning technique where a hash key is used to distribute rows evenly across the different partitions (sub-tables). This is typically used where ranges aren't appropriate, i.e. employee number, productID, etc.

History

Hash partitioning was first introduced in Oracle 8i.

Examples

create table emp2 (
   empno number(4), 
   ename varchar2(30), 
   sal   number
) 
partition by hash(empno) (
  partition e1 tablespace emp1, 
  partition e2 tablespace emp2, 
  partition e3 tablespace emp3,
  partition e4 tablespace emp4
); 

create table emp2 (
   empno number(4), 
   ename varchar2(30), 
   sal   number
) 
PARTITION BY HASH(empno)
PARTITIONS 3
STORE IN (empts1, empts2, empts3);