LUW

[Former Member]

can anyone tell me abt LUW?and purpose of it?

[Former Member]

HI,

<b>What is LUW or Database LUW or Database Transaction ?</b>- A “LUW” ( logical unit of work ) is the span of time during which any database updates must be performed . Either they are all performed ( committed ) , or they are all thrown away ( rolled back ).

<b>LUW ( or “database LUW” or “database transaction” )</b>

This is the set of updates terminated by a database commit. A LUW lasts, at most, from one screen change to the next ( because the SAP system triggers database commits automatically at every screen change ).

LUWs help to guarantee database integrity. When an LUW has been successfully concluded, the database is once again in a correct state. If, however, an error occurs within an LUW, all database changes made since the beginning of the LUW are canceled and the database is then in the same state as before the LUW started.

Go To the link:

http://help.sap.com/saphelp_nw04/helpdata/en/41/7af4bfa79e11d1950f0000e82de14a/content.htm

<b>An LUW begins</b>

- Each time you start a transaction

- When the database changes of the previous LUW have been confirmed (database commit) or

- when the database changes of the previous LUW have been cancelled (database rollback)

An LUW ends

- When the database changes have been confirmed (database commit) or

- When the database changes have been canceled (database rollback)

What is SAP LUW or Update Transaction ?

- Update transaction ( or “SAP LUW”)

This is a set of updates terminated by an ABAP/4 commit. A SAP LUW may last much longer than a database LUW, since most update processing extends over multiple transaction screens.The programmer terminates an update transaction by issuing a COMMIT WORK statement.

Reward points if this Helps.

Manish

[Former Member]

In simple:

Logical Unit of Work holds the data while processing. Ex: If we enter data for a material creation. If there are 5 screens, The data will be stored in the database only when all the screens are duly filled. If we enter only 4 screens of data andcome back, It wont stores the data.

In detail:

When you change resources that are categorized as non-recoverable (such as serial files on Windows® 2000), your work is relatively permanent; neither your code nor EGL run-time services can simply rescind the changes. When you change resources that are categorized as recoverable (such as relational databases), your code or EGL run-time services either can commit the changes to make the work permanent or can rollback the changes to return to content that was in effect when changes were last committed.

Recoverable resources are as follows:

Relational databases

MQSeries® message queues, unless your MQSeries record specifies otherwise, as described in MQSeries support

A logical unit of work identifies input operations that are either committed or rolled back as a group. A unit of work begins when your code changes a recoverable resource; and ends when the first of these events occurs:

Your code invokes the system function sysLib.commit or sysLib.rollback to commit or roll back the changes

Your program executes a transfer with a commit specified

EGL run-time services performs a rollback in response to a hard error that is not handled in your code; in this case, all the programs in the run unit are removed from memory

Cheers.