In simple chaining, load factor is the average number of elements stored in a chain, and is given by the ratio of number of elements stored to the number of slots in the array.

Deletion becomes easier with doubly linked list, hence it is appropriate.

A hash table is used to implement associative arrays which has a key-value pair, so the has table maps keys to values.

Direct addressing is possible only when we can afford to allocate an array that has one position for every possible key.

Since every key has a unique array position, searching takes a constant time.

There are two cases, once when the search is successful and when it is unsuccessful, but in both the cases, the complexity is O(1+alpha) where 1 is to compute the hash function and alpha is the load factor.

On increasing hash table size, space complexity will increase as we need to reallocate the memory size of hash table for every collision. It is not the best technique to avoid a collision. We can avoid collision by making hash function random, chaining method and uniform hashing.

In a hash table, if sevaral elements are computing for the same bucket then there will be a clash among elements. This condition is called Collision. The Collision is reduced by adding elements to a linked list and head address of linked list is placed in hash table.

In simple uniform hashing, any given element is equally likely to hash into any of the slots available in the array.

In a hash table, there are fewer array positions than the keys, so the position of the key in the array has to be computed, this is done using the hash function.