Logical records
COBOL uses the term logical record in a slightly different way than z/OS® QSAM.
For format-V and format-S files, a QSAM logical record includes a 4-byte prefix in front of the user data portion of the record that is not included in the definition of a COBOL logical record.
For format-F and format-U files, and for byte-stream files in the z/OS UNIX file system, the definitions of QSAM logical record and COBOL logical record are identical.
In this information, QSAM logical record refers to the QSAM definition, and logical record refers to the COBOL definition.