Yes, that metalink query is a bunch of crap. Actualy, if you look at its creation date, you'll see that it's from 1994!!!! Those were the days of Oracle7.0, werent they? So to be fair - that query is probably still valid for Oracle7 (and maybe for some later releases), but it certanly is not valid for 9i any more. Since Oracle7, some of the statistics meaning have drasticaly changed, obviously also including "'process last non-idle time".

Besides, when that query was written, that was the only way to obtain the information when a particular session was last active. But nowadays (at least since 8i, maybe even earlier) you have much easier way available to get that information. In V$SESSION there is a column LAST_CALL_ET which displays the time (in seconds) since a particular session isued the last request to the database.