Release Notes - 7.11 Development Release

New release is out and here is the list of bug fixes and improvements that you will find in it: OMN-177 - OMNAddin.addin file location detection fails on non english language OMN-176 - ObjectManagerEnterprise fails to run on non english boxes OMN-175 - In Query result, Empty any cell displaying some primitive value. It throws NullReference Exception OMN-174 - exception occurs on dragging some fileds to attribute list and then running a query or click on view all objects. OMN-173 - Queries not returning correct results for datetime field. OMN-172 - For Bool and datetime fields, query builder does not show dropdown for bool values and calender for datetime OMN-171 - If such a search string is added which has no matching class and we switch to assembly view then the db4o broweser has treeview with just assembly name OMN-169 - Recent queries remains for a db, if the db is deleted and created again with same name and location OMJ-144 - Error by running a query OMJ ... Read the rest of entry »

Improved Exception Handling

In the latest build we have introduced an even stricter Exception handling. The new strategy: If the exception occured is a Db4oRecoverableException we rethrow this exception to the user application. In all other cases we do an emergency shutdown of the ObjectContainer/ObjectServer without commit, without even writing FreeSpace information. This way we try to do our best to keep the database in the last committed state. The new behaviour is quite different to the previous behaviour where we did not catch VM errors. In Client/Server mode an OutOfMemoryError for a specific client would have only terminated the handling thread for the client that it serviced. The server would have continued to work. For this case there was a small risk that BTrees or cache pages ended up in an inconsistent state. The change of the Exception handling is also relevant for single user mode: If db4o would have been accessed by multiple threads, the one thread that experienced an OutOfMemoryException would have died. Other threads ... Read the rest of entry »

Memories - Running db4o in-memory revisited

Running a db4o database completely in main memory certainly is not the most ubiquitous usage. Nevertheless there are quite some users out there who are using db4o that way - caching is one possible use case where this option may be helpful. db4o has supported in-memory use from the very beginning, but it has rather been considered a step child feature. For historical reasons, there have been two redundant, although semantically slightly different ways to start db4o in-memory: As an InMemoryObjectContainer (the legacy variant), or as a vanilla container configured to use MemoryStorage (the "proper" variant). Both options would not fully support all the features the file-based scenario would offer. Here's a brief summary of the current status of db4o in-memory usage. There can only be oneWe eventually decided to deprecate the InMemoryObjectContainer variant. Although code using InMemoryObjectContainer will remain functional, we strongly encourage users to switch to PagingMemoryStorage.Reduced memory consumptio ... Read the rest of entry »