LISTING 2: Skip scan query report for case 1
select *
from
 t t1 where object_id = 55


call        count         cpu        elapsed       disk      query      current      rows
------      -----         ---        -------       ----      -----      -------      ----
Parse           1        0.00           0.01          0          0            0         0
Execute         1        0.00           0.00          0          0            0         0
Fetch           2        0.00           0.00          0          7            0         1
------      -----         ---        -------       ----      -----      -------      ----

total           4        0.00           0.01          0          7            0         1

Rows       Row Source Operation
--------   ---------------------------------------------------
1          TABLE ACCESS BY INDEX ROWID T
1          INDEX SKIP SCAN (object id 19845)