cn=config is special, that's why :) You should generally ignore it for
these discussions about backends and databases.

not to annoy, but what’s special about it? A quick question about the terminology: what’s a backend? The physical db files on disk?

So if you look at the entries from id2entry you'll notice that they
don't have dn's rdns. IE:

uid=william

Does that help?

Well explained. Thank you!

So what are the rules of thumb for choosing the sizes of these databases? Currently, I just set both cache sizes to 3G because I have the memory.