CICS allows us to access file data in many ways. Most file accesses are random in online system as the transactions to be processed are not batched and sorted into any kind of order. Therefore CICS supports the usual direct access methods − VSAM and DAM (Direct Access Method). It also allows us to access data using database managers.
Random Access
Following are the commands which are used for random processing −
| Sr.No | Commands & Description |
|---|---|
| 1 | READREAD command reads data from a file using primary key. |
| 2 | WRITEWrite command is used to add new records to a file. |
| 3 | REWRITEREWRITE command is used to modify a record that is already present in a file. |
| 4 | DELETEDELETE command is used to delete a record that is present in a file. |
Sequential Access
Following are the commands which are used for sequential processing −
| Sr.No | Commands & Description |
|---|---|
| 1 | STARTBRSTARTBR is known as start browse. |
| 2 | READNEXT / READPREVWhen we issue a STARTBR command, it does not make the records available. |
| 3 | RESETBRThe RESETBR command allows us to reset our starting point in the middle of a browse. |
| 4 | ENDBRWhen we have finished reading a file sequentially, we terminate the browse using the ENDBR command. |