I wonder how many databases still use YYMMDD date formats (i.e. with date
windowing) and have fields of this type as sort items?

Dates have always been popular sort items since as long as the current date
is used then new entries will sort/be added to the end of the sorted chain
in the database, which is an efficient operation in Image.

Of course now that a two digit YY date starts with "00", every DBPUT is
going to have to read the entire dataset serially (backwards) before it
finds the appropriate place in the chain at which to insert the entry!

This will of course quietly result in amazingly bad performance rather than
any overt failure of the application.

The Growthpower "hang" described earlier this morning sounds a lot like what
one would expect in the case of this kind of problem.

Something to be on the lookout for.

I suppose it's too late to bring up performance as an area of Y2K impact
concern such that one would want to have a good characterization of the
performance of one's system before the Y2K rollover in order to be able to
detect Y2K impacts like this.

G.