Oracle Database 12.2 New Feature => Re-order Table Online and Its Effect on Index Performance

With 12cR2, we can re-order our tables online according to any column.

Create and Fill table:
 

Order By empid:

Order By empname:

Performance Effect:

Reordering table can improve the performance of index access because if the table is ordered according to index column, we need to visit less leaf blocks and it will reduce the logical I/O.

Dummy Table:

Create a dummy table with 1.000.000 rows:

Create index on empid:

Check Plan and Statistics