#include <db_cxx.h> int DbEnv::txn_checkpoint(u_int32_t kbyte, u_int32_t min, u_int32_t flags) const;
         If there has been any logging activity in the database environment
         since the last checkpoint, the DbEnv::txn_checkpoint() method
         flushes the underlying memory pool, writes a checkpoint record to the
         log, and then flushes the log.
    
         The DbEnv::txn_checkpoint() method returns a non-zero error value on
         failure and 0 on success.
    
         The DbEnv::txn_checkpoint() method is the underlying method used by
         the db_checkpoint
         utility. See the db_checkpoint utility
         source code for an example of using DbEnv::txn_checkpoint() in a
         IEEE/ANSI Std 1003.1 (POSIX) environment.
    
The flags parameter must be set to 0 or the following value:
                  DB_FORCE
            
Force a checkpoint record, even if there has been no activity since the last checkpoint.
If the kbyte parameter is non-zero, a checkpoint will be done if more than kbyte kilobytes of log data have been written since the last checkpoint.
                         The DbEnv::txn_checkpoint() 
            
            
                method may fail and throw a DbException 
                exception, encapsulating one of the following non-zero errors, or return one
                of the following non-zero errors: