What file access method combines the advantages of both sequential and direct access by using an index file?

The file access method that combines the advantages of both sequential and direct access is known as indexed file access. This method utilizes an index file that allows for efficient searching and retrieval of records, much like direct access, while also maintaining the ability to access records in a sequential manner.

In indexed file access, an index is created which stores references to the actual data records. This index allows the system to quickly locate a specific record without needing to read through all preceding records, thus expediting the retrieval process. If a user wants to access records sequentially, they can simply follow the order of the records as they are stored, which is beneficial for operations that require processing data in a particular sequence.

Overall, indexed file access effectively merges the rapid retrieval capabilities of direct access with the systematic processing of sequential access, providing flexibility in how data can be accessed and organized.