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From Knut Anders Hatlen <Knut.Hat...@Sun.COM>
Subject Re: Issues with open files in Derby
Date Tue, 15 Jun 2010 18:37:27 GMT
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

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