db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Luke Quinane" <l...@nuix.com>
Subject RE: Concurrent Derby access
Date Thu, 19 Mar 2009 01:07:13 GMT
Hi Bryan,

Unfortunately copying the databases is too costly in terms of disk space and
the time required to copy the data. Our databases are usually tens of
gigabytes in size and may be accessed by 20 or more different processes at
the same time.

I'm quite happy to modify Derby to ensure that the reading processes will
access the database in read-only mode, but is this safe if the database is
being updated at the same time?

Thanks in advance,


-----Original Message-----
From: Bryan Pendleton [mailto:bpendleton@amberpoint.com] 
Sent: Thursday, 19 March 2009 12:34 AM
To: Derby Discussion
Subject: Re: Concurrent Derby access

> Our application currently uses a Derby database running as an embedded 
> instance. I've recently experimented making the database files read-only 
> so that multiple processes can read the database concurrently. 

If multiple instances of your application want to have read-only
embedded access to the same data, why not just make a copy of the
actual database and include the copy as part of each instance of
the application?

You could physically embed the database into your application, by
packaging it as a jar in your classpath, or you could do this by
having an installation procedure which installs a separate copy of
the database for each installed copy of the application.



View raw message