Re: On disable_cost

[Alexander Lakhin]

Hello Richard,

06.09.2024 12:51, Richard Guo wrote:

Ah I see.  label_sort_with_costsize is only used to label the Sort
node nicely for EXPLAIN, and usually we do not display the cost
numbers in regression tests.

In fact, I see the error with the following (EXPLAIN-less) query:
create table t (x int);

select * from t natural inner join
(select * from (values(1)) v(x)
  union all
 select 1 from t t1 full join t t2 using (x),
               t t3 full join t t4 using (x)
);

2024-09-06 10:01:48.034 UTC [696535:5] psql LOG:  statement: select * from t 
natural inner join
    (select * from (values(1)) v(x)
      union all
     select 1 from t t1 full join t t2 using (x),
                   t t3 full join t t4 using (x)
    );
createplan.c:5457:6: runtime error: 4.99254e+09 is outside the range of 
representable values of type 'int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior createplan.c:5457:6 in

(An UBSan-enabled build --with-blocksize=32 is required for this query to
trigger the failure.)

Best regards,
Alexander