Inserting a Data Entry into a B+ Tree
Put data entry onto L.
- If L has enough space, done!
- Else, must split L (into L and a new node L2)
- Redistribute entries evenly, copy up middle key.
- Insert index entry pointing to L2 into parent of L.
This can happen recursively
- To split index node, redistribute entries evenly, but push up middle key. (Contrast with leaf splits.)
Splits “grow” tree; root split increases height.
- Tree growth: gets wider or one level taller at top.