The DbMpoolFile::close method closes the source file indicated by the
DbMpoolFile object. Calling DbMpoolFile::close does not imply
a call to DbMpoolFile::sync, i.e. no pages are written to the source
file as as a result of calling DbMpoolFile::close.
In addition, if the file argument to DbMpoolFile::open was NULL,
any underlying files created for this DbMpoolFile will be removed.
Once DbMpoolFile::close has been called, regardless of its return, the
DbMpoolFile handle may not be accessed again.
The DbMpoolFile::close method either returns a non-zero error value or throws an exception that
encapsulates a non-zero error value on failure, and returns 0 on success.
Errors
The DbMpoolFile::close method may fail and throw an exception or return a non-zero error for errors specified for other Berkeley DB and C library or system methods.
If a catastrophic error has occurred, the DbMpoolFile::close method may fail and either
return DB_RUNRECOVERY or throw an exception encapsulating
DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail
in the same way.