What does bnum exactly mean in tokyo tyrant

Question

1. What does bnum exactly mean in tokyo tyrant, can someone explain it with an example?

2. If the size of the tch data file exceeds 2GB, what should I do?

Answer 1

1. bnum is (probably) the size of the hash. when full, you will see collisions. see Why does tokyo tyrant slow down exponentially even after adjusting bnum?
2. open the file with TLARGE option.