Final answer:
Linear hashing does not guarantee at most one disk access to retrieve a record with a given key value, especially during table expansion or if key is in an overflow chain. While it aims to minimize multiple disk accesses, it cannot ensure a single access for each retrieval.
Step-by-step explanation:
The student is asking about linear hashing and whether it can guarantee at most one disk access to retrieve a record with a given key value. Linear hashing is a dynamic hashing method that allows for the gradual expansion of the hash table so that the distribution of data across the buckets can remain even as new data is inserted. However, while linear hashing aims to limit the number of disk accesses, it does not always guarantee that only a single disk access will be necessary for each record retrieval. There are situations, particularly during the process of hash table expansion or overflow, where more than one disk access may be required to retrieve a record.
The key feature of linear hashing is its ability to spread out the rehashing process over time, which means that insert operations are generally less expensive because they don't require immediate rehashing and redistribution of all records. Nonetheless, when a search for a specific key is conducted and that key is in an overflow chain, multiple disk accesses might be required to find the record. Therefore, while linear hashing is designed to reduce the likelihood of multiple disk accesses, it is not guaranteed in every case.