Question

Assuming a table with a column where integers are stored.

-----------------------------
id    |  some_int  | some_other_value
-----------------------------
1        5           hello
2        9           how
3        987         are
4        5           you
5        9           thanks
6        1           for
7        5           answering. :-)

Is SELECT * FROM mytable ORDER BY some_int; distinct? Meaning will it always return the rows in the same order, after each query?

Answer 1

To the best of my knowledge if there are duplicates in the order by clause, there is no guarantee for the order in which the duplicates are presented.

If this is a concern, you could modify the order by to include the primary key (id I am assuming).

ORDER BY some_int, id

Since id is a primary key, it should also be indexed. Thus the performance difference will be minimal.