information:extraction, stylistic:style_transfer, structural:expansion
Other data structures for separate chaining

If the keys are ordered, it could be efficient to use " self-organizing " concepts such as using a self-balancing binary search tree, through which the theoretical worst case could be brought down to O (log n) {\displaystyle O(\log {n})}, although it introduces additional complexities.

In dynamic perfect hashing, two-level hash tables are used to reduce the look-up complexity to be a guaranteed O (1) {\displaystyle O(1)} in the worst case. In this technique, the buckets of k {\displaystyle k} entries are organized as perfect hash tables with k 2 {\displaystyle k^{2}} slots providing constant worst-case lookup time, and low amortized time for insertion. A study shows array-based separate chaining to be 97% more performant when compared to the standard linked list method under heavy load.

Techniques such as using fusion tree for each buckets also result in constant time for all operations with high probability.