RE: Multiple Data Contexts?

From: Dave Merrin (dmerri..pasystems.co.uk)
Date: Mon Jan 23 2006 - 09:48:45 EST

  • Next message: Gentry, Michael \(Contractor\): "RE: Multiple Data Contexts?"

    Hi,

    currently I have a client server architecture. The client is a java applet
    which does nothing more than call an api on the server. The server then does
    all the database work. I was wondering whether this would need a DataContext
    per client connection or whether a single DataContext could service all
    client connections.

    The architecture may well be expanded to have web applications. I'm not
    entirely sure about the architecture for this part at the moment.

    As for the transactions the client will mainly be querying the database
    rather than doing any updates. That is why I haven't looked too far into the
    container manager transactions.

    Does this help explain a little more?

    Cheers,

    Dave

    > -----Original Message-----
    > From: Gentry, Michael (Contractor) [mailto:michael_gentr..anniemae.com]
    > Sent: 23 January 2006 14:32
    > To: cayenne-use..bjectstyle.org
    > Subject: RE: Multiple Data Contexts?
    >
    >
    > I'm not sure what your application is trying to do, but if it is
    > session-based (web application), you generally want at least one
    > DataContext per session. Also, many portions of DataContext are
    > synchronized, such as commitChanges(), so you wouldn't have 10 parallel
    > commits within a single DataContext. A commitChanges does all of it's
    > work within a single transaction unless you are using the container
    > managed transactions, which relies on the container for transaction
    > management.
    >
    > If you could tell us a bit more about what you are trying to accomplish,
    > we could provide more advice.
    >
    > /dev/mrg
    >
    >
    > -----Original Message-----
    > From: Dave Merrin [mailto:dmerri..pasystems.co.uk]
    > Sent: Monday, January 23, 2006 7:00 AM
    > To: cayenne-use..bjectstyle.org
    > Subject: Multiple Data Contexts?
    >
    >
    > Hi,
    >
    > I'd like to know if it is worth creating any more than one DataContext
    > for
    > the same database? i.e. if I want to be able to run 10 database queries
    > at
    > once is there any need for 10 DataContext objects? Will the underlying
    > connection pooling sort this out for me?
    >
    > What would happen if I brought in a transaction system to deal with
    > database
    > transactions? Would starting a transaction automatically take one of the
    > connections for the entire period the transaction is open?
    >
    > Cheers,
    >
    > Dave
    >

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