As of Informix version 11.50, there is a simple but cool onconfig parameter – MSG_DATE. It puts a date at the beginning of each online log message. That’s a real relief for all us parsing our online logs to get some kind of daily report or similar. It was much harder to determine where the messages of the actual day start before MSG_DATE was introduced, but now you can simply grep the log for the date.
The only not-so-great thing about it is that the date is always in MM/DD/YY format. It doesn’t depend on localization settings. Date formats in log messages could be different from one log to another (e.g. online log and onbar activity log), which makes the parsing of several logs more demanding (or should I say, kind of pain in the a..). Nevertheless, very useful parameter, which IMHO, should be defaulted to 1. It can be changed online using onmode -wf or -wm.