Segmentation fault on a query from table expression

[monetdb-team]

Date: 2014-01-14 15:31:17 +0100
From: Alex Shestakov <<shura.shestakov>>
To: MonetDB5 devs <>
Version: 11.15.19 (Feb2013-SP6)
CC: @mlkersten, @drstmane

Last updated: 2014-02-20 15:02:45 +0100

Comment 19446

Date: 2014-01-14 15:31:17 +0100
From: Alex Shestakov <<shura.shestakov>>

User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.63 Safari/537.36
Build Identifier:

I have a table DailyData defined as follows.

create table DailyData (
sym varchar(32),
businessdate date,
closePrice float,
adjustedClosePrice float,
openingPrice float,
accVol float,
unique(businessdate, sym)
);

I make the following query.

with dd as (select * from DailyData where businessdate > '2013-06-01'),
r as (select t.businessdate, t.sym, 1 - t.adjustedcloseprice / y.adjustedcloseprice as ret from dd t
left outer join dd y on t.businessdate = y.businessdate + (interval '1' day) and t.sym = y.sym),
v as (select sym, stddev_samp(ret) as volatility from r group by sym)
select * from v where v.sym like '%.L' limit 100;

It results in a segmentation fault:

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f5f17023700 (LWP 25178)]
0x0000003ee9327a9a in __strcmp_sse42 () from /lib64/libc.so.6
(gdb) where
0 0x0000003ee9327a9a in __strcmp_sse42 () from /lib64/libc.so.6
1 0x00007f6f2d4ef6f8 in rel_use_index (changes=, sql=0x7f5f08005470, rel=0x7f5f0850aa70) at rel_optimizer.c:4829
2 0x00007f6f2d4ea225 in rewrite (sql=0x7f5f08005470, rel=0x7f5f0850aa70, rewriter=0x7f6f2d4ef610 <rel_use_index>, has_changes=0x7f5f17022cac) at rel_optimizer.c:6106
3 0x00007f6f2d4ea2bc in rewrite (sql=0x7f5f08005470, rel=0x7f5f0850cb40, rewriter=0x7f6f2d4ef610 <rel_use_index>, has_changes=0x7f5f17022cac) at rel_optimizer.c:6093
4 0x00007f6f2d4ea2bc in rewrite (sql=0x7f5f08005470, rel=0x7f5f0850ec30, rewriter=0x7f6f2d4ef610 <rel_use_index>, has_changes=0x7f5f17022cac) at rel_optimizer.c:6093
5 0x00007f6f2d4ea2bc in rewrite (sql=0x7f5f08005470, rel=0x7f5f0850ef50, rewriter=0x7f6f2d4ef610 <rel_use_index>, has_changes=0x7f5f17022cac) at rel_optimizer.c:6093
6 0x00007f6f2d4ea2bc in rewrite (sql=0x7f5f08005470, rel=0x7f5f08512a90, rewriter=0x7f6f2d4ef610 <rel_use_index>, has_changes=0x7f5f17022cac) at rel_optimizer.c:6093
7 0x00007f6f2d4ea2bc in rewrite (sql=0x7f5f08005470, rel=0x7f5f0850feb0, rewriter=0x7f6f2d4ef610 <rel_use_index>, has_changes=0x7f5f17022cac) at rel_optimizer.c:6093
8 0x00007f6f2d4ea2bc in rewrite (sql=0x7f5f08005470, rel=0x7f5f085101c0, rewriter=0x7f6f2d4ef610 <rel_use_index>, has_changes=0x7f5f17022cac) at rel_optimizer.c:6093
9 0x00007f6f2d4ecf58 in _rel_optimizer (sql=0x7f5f08005470, rel=, level=0) at rel_optimizer.c:6278
10 0x00007f6f2d484369 in sql_symbol2relation (c=0x7f5f08005470, sym=) at sql.mx:1755
11 0x00007f6f2d454b2f in SQLparser (c=0x7f6f2df49308) at sql_scenario.c:1708
12 0x00007f6f352ecdd3 in runPhase (c=0x7f6f2df49308) at mal_scenario.c:522
13 runScenarioBody (c=0x7f6f2df49308) at mal_scenario.c:558
14 0x00007f6f352ecf1f in runScenario (c=0x7f6f2df49308) at mal_scenario.c:586
15 0x00007f6f352ed778 in MSserveClient (dummy=0x7f6f2df49308) at mal_session.c:446
16 0x0000003ee9a07851 in start_thread () from /lib64/libpthread.so.0
17 0x0000003ee92e890d in clone () from /lib64/libc.so.6

Apparently at rel_optimizer.c:4829 strcmp(exp_relname(nre) returns NULL which is not checked.

If I rewrite the query in the following way it works if not very fast.

with r as (select t.businessdate, t.sym, 1 - t.adjustedcloseprice / y.adjustedcloseprice as ret from DailyData t
left outer join DailyData y on t.businessdate = y.businessdate + (interval '1' day) and t.sym = y.sym
where t.businessdate > '2013-06-01'),
v as (select sym, stddev_samp(ret) as volatility from r group by sym)
select * from v where v.sym like '%.L' limit 100;

Reproducible: Always

Comment 19447

Date: 2014-01-14 15:58:19 +0100
From: @mlkersten

Not confirmed on the main trunk.

Comment 19448

Date: 2014-01-14 16:54:00 +0100
From: @drstmane

Confirmed (i.e., segfault does occur) with Feb2013-SP6.

Comment 19449

Date: 2014-01-14 16:55:30 +0100
From: @drstmane

Query appears to work fine (on empty table) with the Jan2014 release candidate branch.

Comment 19450

Date: 2014-01-15 14:50:06 +0100
From: Alex Shestakov <<shura.shestakov>>

I can confirm that the bug is fixed in Jan2014 release candidate.

Comment 19465

Date: 2014-01-20 15:16:47 +0100
From: MonetDB Mercurial Repository <>

Changeset 1bcf7aae3e03 made by Sjoerd Mullender sjoerd@acm.org in the MonetDB repo, refers to this bug.

For complete details, see http//devmonetdborg/hg/MonetDB?cmd=changeset;node=1bcf7aae3e03

Changeset description:

Added test for bug #3418.

Comment 19467

Date: 2014-01-20 15:20:21 +0100
From: @sjoerdmullender

Bug seems to be fixed in the upcoming release.

Comment 19606

Date: 2014-02-20 15:02:45 +0100
From: @sjoerdmullender

Jan2014 has been released.