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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