Subject Re: Bi-directional indexes
Author David Johnson
On Sat, 2005-06-25 at 12:42 +0000,
> And one other question. How do other databases handle this problem?

So far as I know, DB2 doesn't. Since it is not generational, it can
scan the index quickly for the last entry, so max (col) can use an
index-only scan. Getting used to the differences between generational
and locking technologies is the big hurdle. Applying both ascending and
descending indexes where it is necessary is not that great of a burden.

I am not sure that bidirectional indexes are that much "superior". IBM,
for all of their flaws, has a pretty good record in large scale
transactional systems, and they haven't implemented bidirectional
indexes in DB2 (or at least we don't use them).