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From David Van Couvering <da...@vancouvering.com>
Subject Re: Issues with open files in Derby
Date Tue, 15 Jun 2010 19:36:45 GMT
I will look at reproducing, but I'm moving towards a workaround where I
don't shut down so much.

I am pretty sure all you need to do is repeatedly kill a process repeatedly
boots, updates, and shuts down a database.  At some point you'll kill the
process in the middle of shutdown and I bet you'll end up with a corrupted

Thanks for the tips on how to reduce the number of open files.  But I
suspect this has a negative impact on performance.  But I can test it out
and see if it's acceptable.


On Tue, Jun 15, 2010 at 11:37 AM, Knut Anders Hatlen <Knut.Hatlen@sun.com>wrote:

> On 06/15/10 12:42 AM, David Van Couvering wrote:
> > So, I have a couple of questions for you all:
> >
> > - Do the number of files held open by a database grow as the number of
> > rows in a table grows?  Some of these tables will have millions of
> > records.
> No, the size of the table shouldn't affect the number of files.
> > - Is there any way to tell Derby to close out open files and/or reduce
> > the number of open files to a minimum?
> There's an undocumented property, derby.storage.fileCacheSize, that
> allows you to tune the size of the container cache (which contains file
> handles for files in the seg0 directory). Its default size is 100.
> Minimum is 2.
> > - Is it a known issue that shutting down a database will corrupt the
> > database if another thread is updating it?
> Not as far as I know, but if you have a reproduction for this, please
> file a bug report. Shutdown was one of the suspects in the still
> unresolved data corruption issue DERBY-3607, but unfortunately no one
> except the reporter has managed to reproduce it.
> --
> Knut Anders

David W. Van Couvering


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