Workaround MySQL solution for http://stackoverflow.com/q/8888349

so-8888349.sql

CREATE TABLE `input`  (`dt` DATETIME, `r` INT);
CREATE TABLE `output` (`dt` DATETIME, `r` INT);

LOAD DATA INFILE 'input.log'  INTO TABLE `input`  FIELDS TERMINATED BY ' ' LINES TERMINATED BY '\n';
LOAD DATA INFILE 'output.log' INTO TABLE `output` FIELDS TERMINATED BY ' ' LINES TERMINATED BY '\n';

(SELECT *
FROM `input`
INNER JOIN `output`
    ON `output`.`dt` > `input`.`dt` + INTERVAL 5 SECOND
    AND `input`.`r` = `output`.r`)
UNION
(SELECT *
FROM `input`
LEFT JOIN `output`
    ON `input`.`r` = `output`.`r`
WHERE `output`.r` IS NULL);