Motivation
Sequential Searching can be done in O(N) access time, meaning that the number of seeks grows in proportion to the size of the file.
B-Trees improve on this greatly, providing O(Logk N) access where k is a measure of the leaf size (i.e., the number of records that can be stored in a leaf).
What we would like to achieve, however, is an O(1) access, which means that no matter how big a file grows, access to a record always takes the same small number of seeks.
Static Hashing techniques can achieve such performance provided that the file does not increase in time.