bdb or hdb ?

[Kari Mattsson <kari@trivore.com>]

I'm wondering... All documentation I've seen mention hdb as sibling of 
bdb with the only significant difference of being able to rename 
(sub)trees, and thus move them around.

Then there is one config difference: idlcachesize shoud be 4 x cachesize 
when using hdb. For bdb it can be way smaller than cachesize.

If the difference really is this small,

1)  where is the real point in having two almost same back-ends?

2)  why wouldn't everybody use hdb in the first place?

--Kari Mattsson