IBM AS/400 manual Using Commitment Control, Starting and Ending Commitment

Using Commitment Control

Using Commitment Control

This section describes how to use commitment control to process file a group. With commitment control, you ensure one of two outcomes for operations:

¹ all of the file operations are successful (a commit operation)

¹ none of the file operations has any effect (a rollback operation

In this way, you process a group of operations as a unit.

To use commitment control, you do the following:

¹On the AS/400:

1.Prepare for using commitment control:. Use the CL commands CRTJRN (Create Journal), CRTJRNRCV (Create Journal Receiver) and STRJRNP (Start Journal Physical File).

2.Notify the AS/400 when to start and end commitment control: Use commands STRCMTCTL (Start Commitment Control) and ENDCMTCTL

(End Commitment Control). See CLtheReference (Abridged)for informa- tion on these commands.

¹In the RPG program:

1. Specify	commitment	control	(COMMIT) on the file-description specifi
of the	files you	want	under commitment control.

2.Use the COMMIT (commit) operation code to apply a group of c files under commitment control, or use the ROLBK (Roll Back) oper code to eliminate the pending group of changes to files under control. For information on how the rollback function is performed system, refer Backupto theand Recoverymanual.

Note: Commitment control applies only to database files.

Starting and Ending Commitment

Control

The

CL command

STRCMTCTL

notifies

the

system

that

you

want

to

start

commi

ment

control.

The

LCKLVL(Lock

Level)

parameter

allows

you

to

select

the

level

at

whic

are

locked

under

commitment

control. See

“Commitment

Control

Locks”

on

page 308

and

theCL

Programming

manual

for

further

details

on lock

levels.

You can make commitment control conditional, in

the

sense

that

the

dec

whether

to

process

a file under commitment control is made at run ti

information, see “Specifying Conditional Commitment

Control”

on

page 311.

When

you

complete

a

group

of changes with

a

COMMIT

operation, you c

a label to identify the end of the group. In the event of an ab

identification

label

is written to a file, message queue, or data

know

which

group

of

changes is the last group to be completed succe

specify

this

file,

message

queue,

or

data

area

on

the

STRCMTCTL

comma

Before you call any program that processes files specified for com issue the STRCMTCTL command. If you call a program that opens a file

Chapter 16. Accessing Database 307Files