Possible Oracle Bug with "greater than 0" in where Clause

Question

I have a select statement which delivers the wrong number of rows. I can reproduce the problem on Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production and on Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production I can not reproduce it on Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production

Testdata:

CREATE TABLE PERSON AS
SELECT LEVEL AS ID, 'Person_'||LEVEL AS NAME, 10 as maxVal
FROM DUAL 
CONNECT BY LEVEL <= 5;

create table orders as
SELECT LEVEL AS ID, 'Order_'||LEVEL AS NAME
FROM DUAL 
CONNECT BY LEVEL <= 3;

If i try the following Query, i get only 3 Results instead of 5:

select p.*
      from person p
     where (maxVal - (select count(*)
                         from orders o
                        where o.id = p.id)
           )  > 0

If i modify the Query to the following, i get 5 Results (which should be the correct Number):

select p.*
      from person p
     where (maxVal - (select count(*)
                         from orders o
                        where o.id = p.id)
           )  > 1

Also the following modification delivers the correct Result:

select p.*
      from person p
     where (maxVal - (select count(*)
                         from orders o
                        where o.id = p.id)
           )  > 0 + 0

I also get the correct number of Results if i use Bind Variables:

select p.*
      from person p
     where (maxVal - (select count(*)
                         from orders o
                        where o.id = p.id)
           )  > :num

So, is there any (known) Bug if i use "greater than 0"?

Answer 1

It's a bug that came after another bug was patched.

("Bug 17564992 Wrong results with fix for bug 12999577 present My Oracle Support Doc ID 17564992.8")

It has it's own patch (Patch 17564992, we haven't tested) but there is a workaround (that we tested):

alter session set "_fix_control" = '12999577:0';
alter session set "_optimizer_squ_bottomup"= FALSE;