Using hash clusters
In the previous recipe, we introduced index clusters and tested a particular way to load data in a cluster to optimize the storage of rows with the same cluster key value.
In this recipe, we introduce a different kind of cluster—hash clusters. The biggest difference between index clusters and hash clusters is in the way data is accessed given a particular cluster key value.
How to do it...
The following steps will demonstrate the use of hash clusters:
- Connect to the HR schema of the
- Create the cluster:
CREATE CLUSTER EMP_DEPT_CLUSTER (deptid NUMBER(4)) SIZE 8192 HASHKEYS 100;
- Create the first table and populate it with data:
CREATE TABLE CL_DEPARTMENTS CLUSTER EMP_DEPT_CLUSTER (department_id) ...