[MonetDB-users] copy into with 'float' types crashes
Hi,
I am encountering something very strange. (Windows - NovSP1 from CVS)
On some machines I encountered crashes in Monet when doing a copy into on tables with a float column. After trying to investigate, I narrowed it down to this:
Run: 1. CREATE TABLE test (f1 int, f2 float); 2. COPY INTO test from 'filename.txt' using delimiters ',','\n','"' null as '';
the text file contains: 1,1 2,2
This sequence exactly caused a server crash (without any message) on some machines, while on others it didn't. The machines it happened on were: 1. 32 bit XP with 3 GB RAM. 2. 32 bit Vista with 4 GB RAM.
In both cases, changing the column type from float to real worked.
Could it be that float, being a 64 bit floating point, might cause crashes on 32 bit machines?
Is there anything I can to help you get a clearer picture of this?
Thanks.
On 2010-02-03 16:53, Alex Bo. wrote:
Hi,
I am encountering something very strange. (Windows - NovSP1 from CVS)
On some machines I encountered crashes in Monet when doing a copy into on tables with a float column. After trying to investigate, I narrowed it down to this:
Run:
- CREATE TABLE test (f1 int, f2 float);
- COPY INTO test from 'filename.txt' using delimiters ',','\n','"' null as
'';
the text file contains: 1,1 2,2
This sequence exactly caused a server crash (without any message) on some machines, while on others it didn't. The machines it happened on were:
- 32 bit XP with 3 GB RAM.
- 32 bit Vista with 4 GB RAM.
In both cases, changing the column type from float to real worked.
Could it be that float, being a 64 bit floating point, might cause crashes on 32 bit machines?
Is there anything I can to help you get a clearer picture of this?
Thanks.
I have not (yet?) been able to reproduce this. I have tried the official Nof2009-SP1 installer, and also some recent build I made.
Since you're using your own build, you can perhaps try this: start the server, then attach the Visual Studio debugger. Then try the sequence of queries that resulted in the crash. Hopefully you can then see in the debugger where it crashed, and perhaps even why.
In the meantime I'll try some more builds, once I've made them.
I am trying this on a 32 bit XP Pro with 2 GB RAM, formerly the system on which I created the official builds.
Alex,
how much data are you laoding and one which kind of machines does it work?
If your are loadling "lots" of data and the difference between float and real alos inside MonetDB is 64- vs. 32-bit, using 64-bit float iso. 32-bit real might just cause to reach/cross the 32-bit address space limitation and hence memory allocations might fail. Obviously, we should not crash in such case, but we are aware that older versions did, though we spend quite some effort on fixing these problems in the Nov2009-SP1 & Nov2009-SP2 releases.
In you are loading "lots" of data, could you also try the Nov2009-SP2 release?
Stefan
On Thu, Feb 04, 2010 at 09:48:58AM +0100, Sjoerd Mullender wrote:
On 2010-02-03 16:53, Alex Bo. wrote:
Hi,
I am encountering something very strange. (Windows - NovSP1 from CVS)
On some machines I encountered crashes in Monet when doing a copy into on tables with a float column. After trying to investigate, I narrowed it down to this:
Run:
- CREATE TABLE test (f1 int, f2 float);
- COPY INTO test from 'filename.txt' using delimiters ',','\n','"' null as
'';
the text file contains: 1,1 2,2
This sequence exactly caused a server crash (without any message) on some machines, while on others it didn't. The machines it happened on were:
- 32 bit XP with 3 GB RAM.
- 32 bit Vista with 4 GB RAM.
In both cases, changing the column type from float to real worked.
Could it be that float, being a 64 bit floating point, might cause crashes on 32 bit machines?
Is there anything I can to help you get a clearer picture of this?
Thanks.
I have not (yet?) been able to reproduce this. I have tried the official Nof2009-SP1 installer, and also some recent build I made.
Since you're using your own build, you can perhaps try this: start the server, then attach the Visual Studio debugger. Then try the sequence of queries that resulted in the crash. Hopefully you can then see in the debugger where it crashed, and perhaps even why.
In the meantime I'll try some more builds, once I've made them.
I am trying this on a 32 bit XP Pro with 2 GB RAM, formerly the system on which I created the official builds.
-- Sjoerd Mullender
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I am not loading a lot of data at all, this happened to me while trying to import about 100 rows. And on the machines where it happened, I can reproduce it all the time with a 2 row csv.
The only thing that the machines on which it happened have in common, is that they have 4GB RAM installed on and 32 bit windows OS.
I will try to attach Visual studio and see if I can get more info and get back to you with that. I'll also try to build Feb2010 and see if it happens.
Thanks.
Update: I tried it on the Feb2010 stable branch and it still happens.
participants (3)
-
Alex Bo. -
Sjoerd Mullender -
Stefan Manegold