> Using 8k page size and 50 character more or less keys+pointers
> entries, you get roughly 160 index entries per page. The first
> two layers of the B+ tree can address 160^2 records if the
> indeces are full. A third layer addresses 4,096,000 records. A
> max operation against an ascending index on a 4,000,000 row table
> should only need to read three pages maximum. This is consistent
> with the results I achieved in the random read tests. Note that
> my primary key is quite large - using an integer key would result
> in even greater efficiency in indexing.

So this is a small but valid argument against using GUID/UUIDs for the
primary key?
Alan