Our formula for trees is n = b d.
Thus, we have 1,000,000,000 = b3, which gives b = 1,000.
A large branching factor, as found in B-trees, allows a desired record to be found in a large database with a small number of (slow) disk accesses. If the first 2 levels of this tree are kept in memory (1,000 + 1,000,000 items), any record in the billion-record database can be gotten with a single disk access.
Contents Page-10 Prev Next Page+10 Index