There are a number of functions that flush pages from the Berkeley DB shared memory buffer pool to disk. Most of those functions can potentially fail because a page that needs to be flushed is not currently available. However, this is not a hard failure and is rarely cause for concern. In the Berkeley DB 3.2 release, the C++ API (if that API is configured to throw exceptions) and the Java API have been changed so that this failure does not throw an exception, but rather returns a non-zero error code of DB_INCOMPLETE.
The following C++ methods will return DB_INCOMPLETE rather than throw an exception: Db::close, Db::sync, DbEnv::memp_sync, DbEnv::txn_checkpoint, DbMpoolFile::sync.
The following Java methods are now declared "public int" rather than "public void", and will return Db.DB_INCOMPLETE rather than throw an exception: Db.close, Db.sync, DbEnv.txn_checkpoint.
It is likely that the only change required by any application will be those currently checking for a DB_INCOMPLETE return that has been encapsulated in an exception.
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