If there are no deleted records available, RMS appends the record to the end of the RMS data file. A sequential file can have primary keys. Obviously, it is not very practical to have primary keys in a sequential file. They are included to make sequential files consistent with the other file access methods. The RMS user need not know the file organization when using any of the file access functions.
Sequential files can also have secondary key fields.
Since the method for performing secondary key indexing is the same for all three file access methods, this is covered in a later section. Sequential files are not intended to hold the normal data activity of an application. They are more suited for use as temporary files that need to hold data for a short period of time.