COBOL Manual for TNS/E Programs (H06.03+)

Environment Division
HP COBOL Manual for TNS/E Programs—520347-003
6-49
FILE-CONTROL Paragraph
•
Buffered Cache
Buffered cache, enabled by the RESERVE clause when the file is open in
OUTPUT, I-O, or EXTEND mode, is discussed under File-Control Entries for
Sequential Files.
•
HP COBOL Fast I-O (Local Buffering)
HP COBOLFast I-O is an enhancement in input-output performance beyond that of
sequential block buffering or buffered cache. It is available if the files upon which
HP COBOL Fast I-O is to operate meet the criteria under File-Control Entries for
Sequential Files.
•
Performance Penalty for Poorly Organized Indexed File
If a large number of entries have been added to and/or deleted from an indexed
file, accessing its records in sequence requires a significant amount of random
processing; therefore, performance suffers.
Example 6-7. Indexed File With One Alternate Key
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT RECEIVABLES-MASTER
ASSIGN TO "=RECMAST"
ORGANIZATION IS INDEXED
RECORD KEY IS INVOICE-NUMBER
ALTERNATE RECORD KEY IS COMPANY-NAME
WITH DUPLICATES,
FILE STATUS IS IO-STATUS.
...
DATA DIVISION.
FILE SECTION.
FD RECEIVABLES-MASTER
LABEL RECORDS ARE OMITTED
RECORD CONTAINS 39 CHARACTERS.
01 INVOICE-RECORD.
05 INVOICE-NUMBER PICTURE 9(7).
05 COMPANY-NAME PICTURE X(15).
05 INVOICE-DATE PICTURE 9(6).
05 INVOICE-AMOUNT PICTURE S9(9)V99.
...
WORKING-STORAGE SECTION.
01 STATUSES.
03 IO-STATUS PICTURE XX VALUE SPACES.
...