-------- Original Message -------- Subject: RE: PROBLEM WITH MONETDB 5.0 Date: Sat, 7 Jun 2008 23:16:13 +0800 From: Tran Quoc Trung <tqtrung@comp.nus.edu.sg> To: 'Martin Kersten' <Martin.Kersten@cwi.nl> References: <38563.137.132.80.35.1212469981.squirrel@mysoc.nus.edu.sg> <4844E431.2090403@cwi.nl> <3363.137.132.80.35.1212475247.squirrel@mysoc.nus.edu.sg> <4844F364.70601@cwi.nl> Hi Mr. Martin, I have installed MonetDB both by using monetdb-install.h and following the document for expert in the website on Ubuntu 2.6 64-bits. I can use the MonetDB server and client. However, when writing a program (in C) to connect to MonetDB, I encounter the error that libMapi.so require libc-2.7.so (The libc in my system is libc-2.5.so). Are there any solution to handle this situation (b/c I restrict not to upgrade the libc due to using the common server with other project). Could you please help me to take a look at this. Thank you very much Trung. -----Original Message----- From: Martin Kersten [mailto:Martin.Kersten@cwi.nl] Sent: Tuesday, 3 June, 2008 3:32 PM To: tqtrung@comp.nus.edu.sg; Communication channel for MonetDB users Subject: Re: PROBLEM WITH MONETDB 5.0 tqtrung@comp.nus.edu.sg wrote:

Hi, Thank you very much. I also guess the reason due to the size of the operands. Currently, I am running on Linux Fedora Core 8, 32 bit. The cardinality of the opearand s in the range 100,000 to 1,500,000 records.

the sizes themselves are not a problem, but the expected size of the join result could be. you could take a sample to see how it explodes (algebra.sample())

Are there any other solutions if my machine could not play with those queries. Please help me to check it again.

Thanks, Trung

...

tqtrung@comp.nus.edu.sg wrote:

...

Dear all, I am a PhD student at School of Computing, NUS, Singapore. Currently, I used MonetDB as the DBMS to do some experiments. I issue a query with about 10 joins, but the system responds with the following errors:

Please inform us about the platform and distribution you are useing.

...

!MALException:algebra.join:GDKerror !ERROR: GDKload: cannot mmap(): name=45/4542, ext=head.priv !OS: Cannot allocate memory

this typically is an error when the join algorithm can not allocated enough memory to hold the intermediate result. For example, on a 32-bit system this might cause a problem quickly. If the join result should fit in memory, then there might be a problem in the estimation of the intermediate size needed. For this we need more information, such as the cardinality of the operands and properties obtained by bat.info()

...

!ERROR: GDKload failed: name=45/4542, ext=head.priv !ERROR: GDKload: cannot mmap(): name=45/4542, ext=tail.priv !OS: Cannot allocate memory !ERROR: GDKload failed: name=45/4542, ext=tail.priv !ERROR: GDKload: cannot mmap(): name=45/4542, ext=head.priv !OS: Cannot allocate memory !ERROR: GDKload failed: name=45/4542, ext=head.priv !ERROR: GDKload: cannot mmap(): name=45/4542, ext=head.priv !OS: Cannot allocate memory !ERROR: GDKload failed: name=45/4542, ext=head.priv !ERROR: GDKload: cannot mmap(): name=44/4401, ext=tail.priv !OS: Cannot allocate memory !ERROR: GDKload failed: name=44/4401, ext=tail.priv

I also try to change the parameter in monetdb5.conf about the memory: gdk_maxsize and gdk_vm_minsize but it still does NOT work.

please don't play with these settings. They only control a thread for flushing dirty pages to disk.

...

Could you please help me to figure out which parameters I could change to make it work.

Thank you very much Trung