Hi,

thanks for the information, but unfortunately this information is not 
helpfull for me. 

Is there a way to configure LMDB on Windows 32 bit, so that a database can 
be larger?
Or is it mandantory to use 64 bit with lmdb (at least on windows file 
systems) when handling larger data?

Regards,
Frank




Von:    Kristoffer Sjögren <[email protected]>
An:     Frank Offermanns <[email protected]>, 
Kopie:  [email protected]
Datum:  28.01.2015 16:32
Betreff:        Re: LMDB usage on windows - to much memory needed



Regarding size.

"If an application specifies a size for the file mapping object that is 
larger than the size of the actual named file on disk and if the page 
protection allows write access (that is, the flProtect parameter specifies 
PAGE_READWRITE or PAGE_EXECUTE_READWRITE), then the file on disk is 
increased to match the specified size of the file mapping object. If the 
file is extended, the contents of the file between the old end of the file 
and the new end of the file are not guaranteed to be zero; the behavior is 
defined by the file system. If the file on disk cannot be increased, 
CreateFileMapping fails and GetLastError returns ERROR_DISK_FULL."

http://msdn.microsoft.com/en-us/library/windows/desktop/aa366537%28v=vs.85%29.aspx

On Wed, Jan 28, 2015 at 3:27 PM, Frank Offermanns <
[email protected]> wrote:
Hello, 

we would like to change our backend from hdb to mdb. 

I did some initial tests and found out the following: 
When setting maxsize to 1.4 GB, the size of the database on the file 
system is about 1.4 GB. I thought I read that the maxsize has nothing to 
do with the actual physical size needed. (If I have only 10 MB of data my 
database should be about 10 MB). 
Even worse is the fact, that slapd.exe then needs about 1.5 GB virtual 
size memory. 
And if I use 32 Bit slapd.exe the process will crash when reaching 2 GB 
virtual size. (as every 32 bit process will do) 

Now my conclusion is, that the things described in the mdb paper are only 
valid for unix/linux, because windows uses another memory system. Is this 
correct? Or is there a way I haven't found to configure OpenLDAP on 
windows so that it does not need so much RAM. 
The size on the disk does not matter for us, but since we use only 32 bit 
slapd.exe the RAM does matter. 

Best regards, 
Frank 

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