Competent data structure used in RDBMS

Question

What is the competent data structure used within the internal storage representation in RDBMS?

Answer 1

B+ tree is the efficient data structure. Since in B+ tree, each data is stored only within leaf nodes, which makes searching simpler. It corresponds to the records which shall be stored within leaf nodes.

It considers all the keys within nodes except the leaves like dummies. Each and every key are duplicated into the leaves. It has the benefit that is all the leaves are linked together sequentially; the whole tree might be scanned without visiting the higher nodes whatever.