Flushes any cached information for this database to disk; only applicable for deferred-write databases.
Note that deferred-write databases are automatically flushed to disk when the {@link #close} method is called.
@see DatabaseConfig#setDeferredWrite DatabaseConfig.setDeferredWrite
@throws com.sleepycat.je.rep.DatabasePreemptedException in a replicatedenvironment if the master has truncated, removed or renamed the database.
@throws OperationFailureException if this exception occurred earlier andcaused the transaction to be invalidated.
@throws EnvironmentFailureException if an unexpected, internal orenvironment-wide failure occurs.
@throws UnsupportedOperationException if this is not a deferred-writedatabase, or this database is read-only.
@throws IllegalStateException if the database has been closed.