Hi,
I would like you to explain the behavior, that is the evaluation process and order of the following statement.

Starting point, two simple tables as follows:

Table "A":
COL_A
----
1
2
3
4

Table "B":
COL_B
----
1
2
3
5

Statement executed:
select a.col_a, b.col_b
from a join b
on a.col_a=b.col_b
where b.col_b <> 5

Result:
COL_A COL_B
----- -----
1 1
2 2
3 3

3 rows selected.

Why I keep expecting that left join would return row from table "A" with col_A = 4 with a corresponding null for col_B?

Sorry in advance if the question is silly.

Regards,
Giuseppe

SQL> select a.col_a, b.col_b
  2  from a left outer join b
  3  on a.col_a=b.col_b
  4  and b.col_b <> 5;  <== this is part OF the join

     COL_A      COL_B
---------- ----------
         1          1
         2          2
         3          3
         4

SQL> select a.col_a, b.col_b
  2  from a left outer join b
  3  on a.col_a=b.col_b
  4  where b.col_b <> 5;  <== this is AFTER the join

     COL_A      COL_B
---------- ----------
         1          1
         2          2
         3          3