Sorting of records is sufficient and a necessary condition for creating?

Sorting of records is a necessary but not a sufficient condition for creating an indexed sequential file. An indexed sequential file is a file organization that combines the features of both sequential and indexed files. Records in an indexed sequential file are stored in a sequential order based on the primary key, but an index is created to allow direct access to the records. Sorting the records is necessary to ensure that they are stored in sequential order based on the primary key. However, creating an index is also necessary to allow direct access to the records using the primary key. Therefore, while sorting is necessary, it is not sufficient on its own to create an indexed sequential file.