Brainstorming/HostFerret/SQL/hf checkins

About

Purpose: Rather than log each and every single checkin, we'll just keep statistics about stretches of checkins that fall within expected time-limits. That is, as long as a checkin isn't too late, we'll just treat it as

SQL

<mysql>CREATE TABLE `hf_checkins` (

 `ID`                   INT NOT NULL AUTO_INCREMENT,
 `WhenStart`       DATETIME NOT NULL COMMENT "when the stretch started",
 `ID_Session`           INT NOT NULL COMMENT "session.ID of checkin connection",
 `Stats_Count`          INT NOT NULL COMMENT "number of checkins in this stretch",
 `Stats_DiffSum`        INT NOT NULL COMMENT "SUM(X) where X is interval since previous checkin",
 `Stats_DiffSSq`        INT NOT NULL COMMENT "SUM(X^2)",
  PRIMARY KEY(`ID`)

) ENGINE = InnoDB;</mysql>