Re: Relaxed optimistic locking possible?

From: BL (bleu..mx.de)
Date: Tue Nov 25 2008 - 05:21:59 EST

  • Next message: Lawrence Gerstley: "Re: Using Cayenne with RCP and Birt?"

    On Mon, 24 Nov 2008 18:23:51 -0500 "Mike Kienenberger" <mkienen..mail.com> wrote:

    > Can't you do this already?
    >
    > Each field can be set to be optimistically-locked or unlocked individually.
    >
    > It might require manually changing your map entity definition in the
    > run-time if this behavior isn't constant, but that doesn't seem like a
    > big deal.

    Not only at runtime, it changes within the active sync process.

    Just to be sure: DataNodeSyncQualifierDescriptor.reset seems to call attribute.isUsedForLocking to detect attributes it has to add to the qualifier (I think you wrote this part)?.

    Is it possible to influence this process from outside - without knowledge of the ObjectDiff - while the query appending happens? This would be great, but I don't see it. Do you have a hint for me?

    BTW: What's the best practice to implement this without getting problems in the next Cayenne release?

    Thanks for your help.

    > On Fri, Nov 21, 2008 at 9:54 AM, BL <bleu..mx.de> wrote:
    >> the idea is to have a table related setting to request optimistic
    >> locking for the changed properties only. This would allow shared write
    >> access for clients using a distinct set of fields.
    >>
    >> Without global support a customized UpdateBatchQueryBuilder could
    >> do it probably locally, only access to the snapshot (getChangesByObjectId)
    >> of the current entity would be required.
    >>
    >> Is there any interest in such a feature?

    -- 
    Sensationsangebot nur bis 30.11: GMX FreeDSL - Telefonanschluss + DSL 
    für nur 16,37 Euro/mtl.!* http://dsl.gmx.de/?ac=OM.AD.PD003K11308T4569a
    



    This archive was generated by hypermail 2.0.0 : Tue Nov 25 2008 - 05:22:33 EST