Expire Query Cache

Removal probably isn't what you would want in any case, because plucking an Entity out of the cache when other things potentially have active references to it could cause many different kinds of disruption.

What might be desirable, on the other hand, would be to have the entities updated in place. That's exactly what we do when you retrieve copies of entities you already have in the cache (using EntityQueries, Refetch, navigation, or any other mechanism for data retrieval).  We make a number of different MergeStrategies available for doing this, but the default is that we will update the existing entity in the cache as long as it doesn't have unsaved changes.

We don't supply a setting on the EntityManager to do this automatically, but we do provide a number of mechanisms that permit you to accomplish what you want. In general it's good to be as specific as possible about what you really need refreshed, as it's not hard to impair performance if you're a bit too gratuitous in retrieving and re-retrieving data.

On platforms other than Silverlight, we have a push notification facility that allows you to invoke a method on the Business Object Server which then stays alive and does any operation you need, such as requerying the database at a specified interval, determining if any entities have changed, and then calling the client to let it know that they have. When we implemented push, the necessary infrastructure wasn't available in Silverlight. It now is, but we simply haven't gotten back around to push for that platform yet. It's on our list.

It's often not the best solution in any case. You (the developer) can generally figure out which entities go stale at what intervals, or in which parts of the application (and when the user does what) those entities need to be brought into currency. If you're writing on online ticket sales application, for example, you'd surely want to provide current data to the sales clerk about what seats remain unsold when she's talking with a customer. But you could give her a button to demand that when a customer inquires about a given event, for example.

So, lots of mechanisms. If you like, say more about your use case and perhaps we can suggest a specific strategy.

• Stale Entity Data
• Query Workflow
• Query Strategy
• Fetch Strategies
• Merge Strategies

• Forced Re-Fetch
• Merge Strategy in More Detail