On 09. april 2014 17:51, Rick Hillegas wrote:
On 4/8/14 2:00 AM, Chux wrote:
Hey Dag,
Thanks for your insight.
I'm using this as an embedded DB in a Java FX desktop application.
This is a dumb question but would you recommend shutting down the
database ever after a transaction? Like after you create a record
then you shut it down after commit.
Depends on the application. If the database holds some kind of
infrequently referenced metadata, so that say, it is only queried or
updated once a day, then you could consider an "on demand" model where
the database is booted for each query/update, then the query results
are returned, then the database is shut down so that it doesn't
consume any resources. The big extra cost of an "on demand" database
would be this: query/update time would be substantially longer since
every query/update involves booting the database, compiling the
query/update, and gracefully closing the database; that cost is on top
of the steady-state cost of running a pre-compiled query/update.
In such a scenario one might want to shut down the engine, too, not just
the database.
Note that shutting down the database will resources, but if the engine
is still running, one can further release resources by shutting that
down as well.
Cf. http://db.apache.org/derby/docs/10.10/devguide/tdevdvlp20349.html
(engine shutdown)
and http://db.apache.org/derby/docs/10.10/devguide/tdevdvlp40464.html
(shutdown database)
Thanks,
Dag
Hope this helps,
-Rick
Best,
Chux
On Tue, Apr 8, 2014 at 12:32 AM, Dag H. Wanvik <[email protected]
<mailto:[email protected]>> wrote:
On 06. april 2014 21:02, George Toma wrote:
Hi Chux,
In my opinion the example from app. referred at commit the
transaction OR close the connection ( a connection could be
transacted too ), and not to shutdown the db. If the business
rule specifies that the db. needs to be shutdown when the app. is
shutdown, then so be it.
Normally the db is not shutdown, not even when the app is down.
This is true for a client/server application. For use with
embedded Derby, one would normally close down the database (and
the database engine) before exiting the application. If one
neglects to do so,
one would see longer start-up times as Dyre indicated.
Thanks,
Dag
Cheers,
George
On Sunday, April 6, 2014 7:14 PM, Chux <[email protected]>
<mailto:[email protected]> wrote:
Hello guys,
I read in a sample app that you've got to shutdown a database. I
was just confused if you need to shut it down on every connection
transaction or just shut it down on application close, in my case
a desktop applicaiton.
Best,
Chux
