******************CASE0******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_nn = 0.5
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 is not NULL;
SELECTIVITY = 1

******************CASE1******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_e = 0.1
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 = 1;
SELECTIVITY = 0.1

******************CASE2******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_nn = 0.5
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 > 0;
SELECTIVITY = 1

******************CASE3******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_e + p_e = 0.2
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 = 1 or c1 = 2;
SELECTIVITY = 0.2

******************CASE4******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_e = 0.1
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 = 1;
SELECTIVITY = 0.1

******************CASE5******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_e + p_e - p_e * p_e = 0.19
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 = 1 or c2 = 1;
SELECTIVITY = 0.19

******************CASE6******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_e + p_nn - p_nn * p_e = 0.55
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 > 0 or c1 = 1;
SELECTIVITY = 1

******************CASE7******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_e * p_e + p_e - p_e * p_e * p_e = 0.109
----------------------------------------------------------
EXPR_STR: select c1 from t1 where (c1 = 1 and c2 = 1) or c1 = 2;
SELECTIVITY = 0.109

******************CASE8******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_e ^ 2 + p_e * p_nn - p_e ^ 3 * p_nn = 0.0595
----------------------------------------------------------
EXPR_STR: select c1 from t1 where (c1 = 1 and c2 = 1) or (c1 = 2 and c2 > 0);
SELECTIVITY = 0.0595

******************CASE9******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :(2 * p_e - p_e * p_e) + (p_e * p_nn) - (2 * p_e - p_e * p_e) * (p_e * p_nn)  = 0.2305
----------------------------------------------------------
EXPR_STR: select c1 from t1 where (c1 = 1 or c2 = 1) or (c1 = 2 and c2 > 0);
SELECTIVITY = 0.2305

******************CASE10******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_e ^ 2 + (p_e + p_nn - p_e * p_nn) - (p_e ^ 2 * (p_e + p_nn - p_e * p_nn)) = 0.5545
----------------------------------------------------------
EXPR_STR: select c1 from t1 where (c1 = 1 and c2 = 1) or (c1 = 2 or c2 > 0);
SELECTIVITY = 0.5545

******************CASE11******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :p_e + p_e + p_e + p_e = 0.4
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 = 1 or c1 = 2 or c1 = 3 or c1 = 4;
SELECTIVITY = 0.4

******************CASE12******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :(p_e + p_e + p_e) + p_e - p_e * (p_e * 3) = 0.37
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 = 1 or c1 = 2 or c1 = 3 or c2 = 4;
SELECTIVITY = 0.3439

******************CASE13******************
min = 1, max = 5, ndv = 5, null_num = 5
the ratio of not null row is (10-5)/10 = 0.5
for range cond : if half_open min_selectivity = 20/DNV, else min_selectivity = 10/DNV
EXPECTED RESULT :((p_e + p_e) + p_e - p_e * (p_e + p_e)) + p_e - p_e * (3 * p_e - p_e * (p_e + p_e)) = 0.352
----------------------------------------------------------
EXPR_STR: select c1 from t1 where c1 = 1 or c1 = 2 or c2 = 3 or c1 = 4;
SELECTIVITY = 0.3439