ESDS
Entry-sequenced data set |
KSDS
Key-sequenced data set |
Fixed-length RRDS
Relative record data set |
Variable-length RRDS
Relative record data set |
Linear data sets |
| Records are in the same order as they are entered |
Records are in collating sequence by key field after load |
Records are in relative record number order |
Records are in relative record number order |
No processing at a record level |
| Records can be fixed or variable length |
Records can be fixed or variable length |
Records are fixed length |
Records are variable length |
No processing at a record level |
| Direct access by RBA |
Direct access by key or by RBA |
Direct access by relative record number |
Direct access by relative record number |
Access with Data-In-Virtual (DIV) optionally |
| Consist of a data component only |
Consist of data and index components |
Consist of a data component only |
Consist of data and index components |
Consist of a data component only |
| Alternate index allowed |
Alternate indexes allowed |
No alternate index allowed |
No alternate index allowed |
No alternate index allowed |
| A record’s RBA cannot change |
A record’s RBA can change |
A record’s relative record number cannot change |
A record’s relative record number cannot change |
No processing at a record level |
| Space at the end of the data set is used for adding records |
Free space is used for inserting and lengthening records |
Empty slots in the data set are used for adding records |
Free space is used for inserting and lengthening records |
No processing at a record level |
| A record cannot be deleted, but you can reuse its space for a record of the same length |
Space that is given up by a deleted or shortened record becomes free space |
A slot that is given up by a deleted record can be reused |
Space that is given up by a deleted or shortened record becomes free space |
No processing at a record level |
| Spanned records allowed |
Spanned records allowed |
No spanned records |
No spanned records |
No spanned records |
| Extended format allowed |
Extended format or compression allowed |
Extended format allowed |
Extended format allowed |
Extended format allowed |
