
TABLE_NAME               BLOCKS   NUM_ROWS
-------------------- ---------- ----------
T1                          371      10000

1 row selected.


  NUM_ROWS DISTINCT_KEYS     BLEVEL LEAF_BLOCKS CLUSTERING_FACTOR AVG_LEAF_BLOCKS_PER_KEY AVG_DATA_BLOCKS_PER_KEY
---------- ------------- ---------- ----------- ----------------- ----------------------- -----------------------
     10000           500          2        1111              9745                       2                      19

1 row selected.


COLUMN_NAME           NUM_NULLS NUM_DISTINCT    DENSITY LOW_VALUE                HIGH_VALUE
-------------------- ---------- ------------ ---------- ------------------------ ------------------------
IND_PAD                       0            1          1 782020202020202020202020 782020202020202020202020
                                                        202020202020202020202020 202020202020202020202020
                                                        2020202020202020         2020202020202020

N1                            0           25        .04 80                       C119
N2                            0           20        .05 80                       C114

3 rows selected.

Changing statistics on index t1_i1

PL/SQL procedure successfully completed.


System altered.


Range scan at end of index. This one happens
to default to FTS, so the second attempt is
hinted to use the index


Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=ALL_ROWS (Cost=58 Card=82 Bytes=4756)
   1    0   TABLE ACCESS (FULL) OF 'T1' (TABLE) (Cost=58 Card=82 Bytes=4756)




Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=ALL_ROWS (Cost=93 Card=82 Bytes=4756)
   1    0   TABLE ACCESS (BY INDEX ROWID) OF 'T1' (TABLE) (Cost=93 Card=82 Bytes=4756)
   2    1     INDEX (RANGE SCAN) OF 'T1_I1' (INDEX) (Cost=12 Card=90)




Range scan at start of index. This one defaults
to FTS, so has been hinted to use the index


Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=ALL_ROWS (Cost=264 Card=82 Bytes=4756)
   1    0   TABLE ACCESS (BY INDEX ROWID) OF 'T1' (TABLE) (Cost=264 Card=82 Bytes=4756)
   2    1     INDEX (RANGE SCAN) OF 'T1_I1' (INDEX) (Cost=184 Card=1797)




To show the three selectivities in action
Effective index selectivity set by range scan on 1st column
Effective table selectivity set by n1, ind_pad, n2
Final table selectivity set by all 4 predicates


Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=ALL_ROWS (Cost=264 Card=1 Bytes=58)
   1    0   TABLE ACCESS (BY INDEX ROWID) OF 'T1' (TABLE) (Cost=264 Card=1 Bytes=58)
   2    1     INDEX (RANGE SCAN) OF 'T1_I1' (INDEX) (Cost=184 Card=1797)




Session altered.

