Hi John:

Thanks for your information!

Regards,
Mian


> Hi, Mian,
>
> We are able to confirm that the function ibis::fileManager::unload
> (which printed the warning message) was indeed performing a number of
> computations in 32-bit arithmetic.  They will be changed to use size_t
> in the coming releases.  This should address the problem you've seen.
>
> We are in the process of preparing the next release.  Due to the
> extensive changes involved, it might take some time before we are done
> with all the testing..
>
> John
>
>
> On 10/25/2009 8:28 PM, Mian Lu wrote:
>> Hi John:
>>
>> I have performed the same evaluation multiple times, but it always
>> produced similar warnings. I observed that the actual memory consumed is
>> about half (4G, I have total 8G memory). Moreover, I wonder what
>> happened
>> if the necessary bit vectors cannot fit into the memory since I have
>> found
>> that in sumBits these functions, you need to activate all necessary bit
>> vectors. Can I also adjust the memory size assigned to Fastbit? e.g., I
>> want Fastbit to use as much as possible memory for large data sets.
>>
>> Here are some information about my machine. I only use configure and
>> make
>> commands to build the Fastbit without any modifications:
>>
>> OS: CentOS 5.2, the kernel Linux version is 2.6.18-92.e15.
>> Memory size: 8 GB
>> size_t: 8 bytes
>> long int: 8 bytes
>> int: 4 bytes
>>
>> Regards,
>> Mian
>>
>>> Hi, Mian,
>>>
>>> Thanks for the information.  The warning messages appear odd to me.
>>> For example, the 1st warning message says that the maximum allowed
>>> memory (maxBytes) is about 4GB, the amount of memory used currently
>>> (totalBytes) is only 33 MB, but it can not find enough space for 628
>>> MB.  From what I can see there are plenty of free memory available --
>>> there is probably something computed in 32-bit integer arithmetic that
>>> is causing this problem.  It would be helpful for us to get some
>>> information about your machine and compiler in order to help us locate
>>> the actual cause of these erroneous warnings, more specifically, your
>>> OS version, memory size, sizes of size_t, long int, and int.
>>>
>>> The reason that FastBit can still produce the expected answer because
>>> there are fall-back options in many cases.
>>>
>>> John
>>>
>>>
>>> On 10/25/2009 9:27 AM, Mian Lu wrote:
>>>> Actually when I perform an evaluation for about 15 attributes (each
>>>> attribute size is totally 1GB, and the selectivity for each attribute
>>>> is
>>>> 40%), I will receive some warnings like this:
>>>>
>>>> Warning -- fileManager::unload unable to free enough space for
>>>> 628021720
>>>> bytes (totalBytes=33032688, maxBytes=4182255616)
>>>> Warning -- fileManager::storage is unable to find 628021720 bytes of
>>>> space
>>>> to read file descriptor 3
>>>> Sat Oct 24 19:38:29 2009
>>>> Warning -- column[test2.attr12](INT)::estimateRange -- received a
>>>> std::exception -- storage::ctor(read file) failed
>>>> Warning -- fileManager::unload unable to free enough space for
>>>> 628059044
>>>> bytes (totalBytes=66064972, maxBytes=4182255616)
>>>> Warning -- fileManager::storage is unable to find 628059044 bytes of
>>>> space
>>>> to read file descriptor 4
>>>> Sat Oct 24 19:40:06 2009
>>>> Warning -- column[test2.attr0](INT)::estimateRange -- received a
>>>> std::exception -- storage::ctor(read file) failed
>>>> ......
>>>>
>>>> But the final result is correct. I guess Fastbit does has some memory
>>>> limitations for efficiency reasons. Moreover, I also want to know the
>>>> exact answers. Thanks.
>>>>
>>>> Mian
>>>>
>>>>
>>>>> Hi guys,
>>>>>
>>>>> I am a newbie of fastbit. I do not know whether bitmap index is
>>>>> loaded
>>>>> by
>>>>> fastbit into memory. if so, then the size of the bitmap index will be
>>>>> limited by the memory size of that machine runs fastbit. Can fastbit
>>>>> overcome that problem? If it can't, how many records at most can
>>>>> fastbit
>>>>> build bitmap indices on them?
>>>>>
>>>>>
>>>>> Thanks,
>>>>> Min
>>>>> --
>>>>> My research interests are distributed systems, parallel computing and
>>>>> bytecode based virtual machine.
>>>>>
>>>>> My profile:
>>>>> http://www.linkedin.com/in/coderplay
>>>>> My blog:
>>>>> http://coderplay.javaeye.com
>>>>> _______________________________________________
>>>>> FastBit-users mailing list
>>>>> [email protected]
>>>>> https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users
>>>>>
>>>>
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>>
>>
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