Indexes On A Clustered Table

Oracle Database Enterprise - 12.2.0.1

Hello,

We have a table that has 7 columns, 6 of which form the primary key, and the last one is an attribute column defined as NUMBER(5,3). The last column in the primary key is a number from 1-48 denoting the half-hourly period of a particular day, which means that the first 5 columns of the primary key are being stored in the database 48 times to record a very small attribute column.

So, I was thinking of re-defining the table in a single table cluster as follows ;

CREATE

CLUSTER   my_cluster

        ( col_a    VARCHAR2(3),

          col_b    VARCHAR2(4),

          col_c    VARCHAR2(1),