Records are loaded into a relative record data set in relative record number sequence. The data set is a string of fixed-length slots, identified by a relative record number. When a record is inserted, you can assign the relative record number or allow VSAM to assign the record the next available number in sequence. No index is used.

A checkpoint cannot be taken for a VSAM relative record data set (RRDS) in load mode if direct processing was or is performed.

If a checkpoint is taken with a relative record data set open for load mode nondirect processing and direct processing is performed after the checkpoint (thus affecting data that was loaded before the checkpoint was taken), no attempt is made by restart to reset the data that existed at checkpoint time. After restart, the data set resets to checkpoint status but still contains the results of any direct processing performed on that part of the data set that existed at checkpoint time.