Crash using aggregate function inside a case statement in having clause

29 Jan 2018


      Hello,
Database: MonetDB v11.27.11 (Jul2017-SP3)
I am experiencing a crash when attempting to use an aggregate function
inside a case statement in a having clause.  Below is an example.  One use
case for this is that I am computing a formula on aggregated data, and want
to ensure no divide by zero occurs.  Are case statements in having clauses
supported?  Thanks!
create table "t1" (
    "id" int,
    "c1" varchar(100),
    "d1" int,
    "d2" int
);
insert into "t1" values
(1, 'A', 50, 80),
(2, 'A', 200, 350),
(3, 'A', 89, 125),
(4, 'B', 4845, 13),
(5, 'B', 194, 597),
(6, 'C', 5636, 5802),
(7, 'C', 375, 3405),
(7, 'D', 365, 0),
(7, 'D', 87, 0);
-- Works
select
    "c1",
    sum("d1") as "d1",
    sum("d2") as "d2"
from "t1"
group by "c1"
having sum("d1") < case when 5 > 10 then 500 else 400 end;
-- Works
select
    "c1",
    sum("d1")as "d1",
    sum("d2") as "d2",
    1.0 * sum("d1") / (1.0 * case when sum("d2") > 0 then sum("d2") else
null end) as "formula"
from "t1"
group by "c1";
-- Crashes
select
    "c1",
    sum("d1")as "d1",
    sum("d2") as "d2",
    1.0 * sum("d1") / (1.0 * case when sum("d2") > 0 then sum("d2") else
null end) as "formula"
from "t1"
group by "c1"
having (1.0 * sum("d1") / (1.0 * case when sum("d2") > 0 then sum("d2")
else null end)) > 1;
Looking in merovingian.log:
2018-01-29 14:47:15 ERR test[2879]: *** Error in `/usr/bin/mserver5':
double free or corruption (out): 0x00007f57200ea4b0 ***
2018-01-29 14:47:18 MSG merovingian[504]: database 'test' (2879) has
crashed (dumped core)
2018-01-29 14:49:35 MSG merovingian[504]: database 'test' has crashed after
start on 2018-01-29 14:42:36, attempting restart, up min/avg/max: 0s/0s/0s,
crash average: 1.00 0.20 0.07 (2-0=2)
2

Trevor Andreas

Sjoerd Mullender

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