In B+Tree, the pointer does point to the next-level node, not to the key in the next-level node. The function of the pointer is to connect the upper and lower nodes, and connect the B+Tree in a tree structure, so as to find the required data records in the lower nodes and ensure the query efficiency.
During the adjustment and search process of B+Tree, the position and range of records are usually determined by comparing the size of keys, rather than locating records by pointers. The function of the pointer is mainly to point to the corresponding lower-level node, and to search for data records in the lower-level node. Therefore, the pointer is a bridge connecting nodes and an important part of B+Tree to realize efficient query.