+ /** @brief Copy an LMDB environment to the specified path, with options.
+ *
+ * This function may be used to make a backup of an existing environment.
+ * No lockfile is created, since it gets recreated at need.
+ * @note This call can trigger significant file size growth if run in
+ * parallel with write transactions, because it employs a read-only
+ * transaction. See long-lived transactions under @ref caveats_sec.
+ * @param[in] env An environment handle returned by #mdb_env_create(). It
+ * must have already been opened successfully.
+ * @param[in] path The directory in which the copy will reside. This
+ * directory must already exist and be writable but must otherwise be
+ * empty.
+ * @param[in] flags Special options for this operation. This parameter
+ * must be set to 0 or by bitwise OR'ing together one or more of the
+ * values described here.
+ * <ul>
+ * <li>#MDB_CP_COMPACT - Perform compaction while copying: omit free
+ * pages and sequentially renumber all pages in output. This option
+ * consumes more CPU and runs more slowly than the default.
+ * Currently it fails if the environment has suffered a page leak.
+ * </ul>
+ * @return A non-zero error value on failure and 0 on success.
+ */
+int mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags);
+
+ /** @brief Copy an LMDB environment to the specified file descriptor,
+ * with options.
+ *
+ * This function may be used to make a backup of an existing environment.
+ * No lockfile is created, since it gets recreated at need. See
+ * #mdb_env_copy2() for further details.
+ * @note This call can trigger significant file size growth if run in
+ * parallel with write transactions, because it employs a read-only
+ * transaction. See long-lived transactions under @ref caveats_sec.
+ * @param[in] env An environment handle returned by #mdb_env_create(). It
+ * must have already been opened successfully.
+ * @param[in] fd The filedescriptor to write the copy to. It must
+ * have already been opened for Write access.
+ * @param[in] flags Special options for this operation.
+ * See #mdb_env_copy2() for options.
+ * @return A non-zero error value on failure and 0 on success.
+ */
+int mdb_env_copyfd2(MDB_env *env, mdb_filehandle_t fd, unsigned int flags);
+
+ /** @brief Return statistics about the LMDB environment.