Server crashes when using a prepared statement with a function

12 Jul 2016

      Hello,

I have a SQL function (myFunc) that computes the sum of the records on a
table (tbl1) and returns the sum (along with other attributes) as a
table. tbl1 references tables tbl2 and tbl3 through fk_tbl2_id and
fk_tbl3_id's, respectively.

Since I want to use this function in a Node.js API and the parameters
for the function will come from the users of the API, it is safer to use
a prepared statement to bind the parameters. Whenever I try to execute
the following prepared statement with the function:
...
PREPARE SELECT * FROM myFunc(?, ?, ?);
EXEC (2008, 1, 2);
The server crashes, as shown in the server log and dmesg:
...
2016-07-12 10:56:40 MSG merovingian[3110]: database 'testdb' (19875)
was killed by signal SIGSEGV
...
mserver5[18201]: segfault at 30 ip 00007f2d87be51e4 sp
00007f2d86f63b80 error 4 in lib_sql.so[7f2d87b85000+199000]
The SQL function for myFunc is the following:
...
CREATE FUNCTION myFunc(year int, table2_id int, table3_id int)
RETURNS TABLE(name text, total bigint)
BEGIN
   RETURN (
       SELECT
           'Overall',
           COALESCE(SUM(t1.num_enrollments), 0)
       FROM
           tbl1 AS t1
       WHERE
           t1.census_year = year
           AND
               (CASE(table2_id)
                   WHEN 0 THEN
                     (t1.fk_table2_id > 0)
                   ELSE
                     (t1.fk_table2_id = table2_id)
               END)
           AND
               (CASE(table3_id)
                   WHEN 0 THEN
                     (t1.fk_table3_id > 0)
                   ELSE
                     (t1.fk_table3_id = table3_id)
               END)
   );
END;
I'm running MonetDB v11.21.19 (Jul2015-SP4) on Ubuntu 14.04 LTS.

I could not find any bug reports related to the issue. How can I debug
it further?

Any help is deeply appreciated.

Best regards,
João Victor Risso.

João Victor Risso

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