DML does not use Index
Does anyone know possible cause of this situation?
We created an index on a table that has 6 mil. rows.
When we run batch delete on the table, DML does not use the Index, but does a full table scan that takes 13 hours to complete a delete of 1.5 mil. rows.
The DML looks like that
Delete from table_1 where batch_number = 200809;
We have index on table_1 on Batch_Number column.
Batch_Number values currently have only 3 values: 200809, 200810, 200811
Please help if you can