1. Indexed File Processing
Chapter 15
Indexed File Processing

2. EMPLOYEE.DATA file 000001SAKAGUCHI TORU SA2500001000000
000002KOWOLONEK RANDY SA
000003KIM JIN HR
000004IQBAL JAVID HR
000005CETRULO AMY
000006PEACE JENNIFER SA
000007DAVIS SCOTT HR
000008EDMISTEN JESSIE SA
000009ROBINSONELSENERAPRIL HR
000010BATTLES JOHN HR
000011REED MARY HR
000012EATON NICK SA

3. Creating an Indexed File
When the file is created, special information about the file is stored that allows direct record access based on the key

4. Creating an Indexed File
SELECT EMPLOYEE-FILE ASSIGN TO “EMPLOYEE.DATA” ACCESS IS SEQUENTIAL ORGANIZATION IS SEQUENTIAL.
SELECT EMPLOYEE-FILE ASSIGN TO “EMPLOYEE.DATA” ACCESS IS RANDOM ORGANIZATION IS INDEXED RECORD KEY IS EMPLOYEE-NUMBER.

5. Sample Code IDENTIFICATION DIVISION. PROGRAM-ID. CREATEIND.
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT EMPLOYEE-FILE
ASSIGN TO “EMPLOYEE.DATA”
ORGANIZATION IS INDEXED
RECORD KEY IS EMPLOYEE-NUMBER.
DATA DIVISION.
FILE SECTION.
FD EMPLOYEE-FILE
01 EMPLOYEE-RECORD.
05 EMPLOYEE-NUMBER PIC X(6).
PIC X(45).
PROCEDURE DIVISION.
000-CREATE-EMPLOYEE-FILE.
OPEN OUTPUT EMPLOYEE-FILE
CLOSE EMPLOYEE-FILE
STOP RUN .

6. Indexed Files
The only way that you can identify the type of file being created is by inspecting the SELECT clause.
Your program cannot add two records with the same key value. The key field must be unique in the file.
The records must be in ascending order on the key field.
One of the advantages of indexed files is that you can process them either randomly or sequentially.

7. Adding records to an indexed file
See BUILD program

9. Processing an Indexed File
Your program can:
Add records
WRITE record-name
Modify records
REWRITE record-name
Delete records
DELETE record-name

12. Dynamic File Processing
Your program can “jump” to a position somewhere in the file and then begin processing sequentially.