Methods for Processing Disk Files

Table 19 on page 292 shows the valid entries for positions 28, 34, and file description specification for the various file types and process

subsequent

text

describes

each

method of

processing.

 

 

 

 

 

 

 

 

 

 

Table

 

19.

Processing Methods for DISK Files

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Processing

Method

 

 

 

 

 

Limits

 

Record

 

 

 

File

 

 

 

 

 

 

 

 

Processing

 

Address

 

 

Organization

 

 

 

 

 

 

 

 

(Pos. 28)

 

Type

 

 

 

(Pos. 35)

 

 

 

 

 

 

 

 

 

 

(Pos. 34)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Externally

Described

Files

 

 

 

 

 

 

 

 

 

 

With

Keys

 

 

 

 

 

 

 

 

 

 

 

 

Sequentially

 

 

 

 

Blank

 

K

 

 

 

Blank

Randomly

 

 

 

 

 

Blank

 

K

 

 

 

Blank

Sequential

within

limits

 

L

 

K

 

 

 

Blank

(by record-address file)

 

 

 

 

 

 

 

 

Without

Keys

 

 

 

 

 

 

 

 

 

 

 

Randomly/consecutively

 

Blank

 

Blank

 

 

Blank

 

 

 

 

 

 

 

 

 

 

 

 

 

Program

Described

Files

 

 

 

 

 

 

 

 

 

 

With

Keys

(indexed

file)

 

 

 

 

 

 

 

 

Sequentially

 

 

 

 

Blank

 

A,

D,

G,

P,

I

 

 

 

 

 

 

 

 

 

 

T,

Z,

or

F

Randomly

 

 

 

 

 

Blank

 

A,

D,

G,

P,

I

 

 

 

 

 

 

 

 

 

 

T,

Z,

or

F

Sequential

within

limits

 

L

 

A,

D,

G,

P,

I

(by record-address file)

 

 

 

T,

Z,

or

F

Without

Keys

 

 

 

 

 

 

 

 

 

 

 

Randomly/consecutively

 

Blank

 

Blank

 

 

Blank

By

record-address

file

 

Blank

 

Blank

 

 

Blank

As record-address file

 

Blank

 

Blank

 

 

T

(relative

record

numbers)

 

 

 

 

 

 

 

 

As

record-address

limits

fileBlank

 

A,

D,

G,

P,

Blank

 

 

 

 

 

 

 

 

 

 

T,

Z,

F,

or

 

 

 

 

 

 

 

 

 

 

Blank

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Consecutive Processing

During consecutive processing, records are read in the order they ap

For

output

and

input

files that

do

not use

random functions

(such

as S

SETGT,

CHAIN,

or

ADD),

the ILE RPG compiler defaults to or operates as

SEQONLY(*YES)

had

been

specified on the CL command OVRDBF (Override with

Database File). (The ILE RPG compiler does not operate as though

 

SEQONLY(*YES)

had

been

specified

for

update

files.)

SEQONLY(*YES)

allows

 

multiple records

to

be

placed

in internal

data

management

buffers;

the

then

passed to

the

ILE

RPG compiler

one

at

a

time

on

input.

 

292 ILE RPG for AS/400 Programmer's Guide

Page 315 Page 317
Page 316
Image 316
IBM AS/400 manual Consecutive Processing, Subsequent Text Describes Each Method Processing, Add
Page 315 Page 317

AS/400 specifications

The IBM AS/400, now known as the IBM iSeries, is a midrange computer system that has been a cornerstone of enterprise computing since its introduction in 1988. Designed to provide a robust platform for business applications, the AS/400 is celebrated for its reliability, scalability, and integrated database capabilities.

One of the key features of the AS/400 is its Integrated Operating Environment, which blends hardware and software resources seamlessly. This integration allows businesses to execute diverse workloads, ranging from traditional applications to modern web-based services, all on a single platform. The operating system, OS/400 (now IBM i), offers a rich set of APIs and tools for developers, simplifying application development and management.

Another standout characteristic of the AS/400 is its built-in database, DB2 for i. This powerful relational database management system allows for efficient data handling and provides advanced features such as support for SQL, XML, and JSON, making it easier for businesses to manage their data and integrate it with other systems. The database's tight integration with the operating system enables high performance and security.

In terms of scalability, the AS/400 can accommodate small businesses as well as large enterprises, with the ability to support hundreds of users simultaneously. Its architecture allows for easy upgrades in hardware, meaning that organizations can scale their systems without replacing the entire infrastructure.

Security is another critical attribute of the AS/400. With a sophisticated security model, it offers built-in user authentication, access control, encryption, and auditing capabilities to protect data and applications from unauthorized access.

The AS/400 also supports multiple programming languages, including RPG, COBOL, Java, and PHP, giving organizations the flexibility to choose the development tools that best fit their needs. This diversity helps maintain legacy applications while also developing new ones that leverage modern technologies.

Moreover, the platform supports both traditional green-screen interfaces and modern graphical user interfaces, allowing organizations to transition smoothly into contemporary user experience paradigms.

Overall, the IBM AS/400 stands out as a resilient, flexible, and secure computing platform that enables organizations to effectively manage their business operations, streamline processes, and adapt to changing market demands. Its unique combination of integrated features and capabilities ensures that it remains relevant in today's fast-paced technology landscape.
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