re: updates and more

[Former Member]

HI,

What is the v1,v2 updates. When we can update the database with v1 case & v2 case and how.

rgds

p. krishna prasad

[Former Member]

Hi,

V1 is Synchonous update

V2 is Asynchronous update

V1 denotes for time-critical updates used to updating the actual transaction table where v2 updates denotes non-time-critical updates used for updating statitics tables related to the transaction table

Creating update requests

http://help.sap.com/saphelp_nw04s/helpdata/en/e5/de86f335cd11d3acb00000e83539c3/frameset.htm

Also see http://help.sap.com/saphelp_nw04s/helpdata/en/e5/de86f335cd11d3acb00000e83539c3/content.htm

Regards,

Wenceslaus.

[Former Member]

HI

GOOD

V1 and V2 Update Modules

An update is divided into different modules (see also Update Request). Each module corresponds to an update function module.

There are two types of module.

The SAP System makes a distinction between primary, time-critical (V1) and secondary, non-time-critical (V2) update modules. The system also supports collective runs for function modules that are used on a regular basis.

This distinction allows the system to process critical database changes before less critical changes.

V1 modules describe critical or primary changes; these affect objects that have a controlling function in the SAP System, for example order creation or changes to material stock.

V2 modules describe less critical secondary changes. These are pure statistical updates, for example, such as result calculations.

The V1 modules are processed consecutively in a single update work process on the same application server. This means that they belong to the same database LUW and can be reversed. Furthermore, V1 updates are carried out under the SAP locks of the transaction that creates the update (see The SAP Lock Concept). This ensures that the data remains consistent; simultaneous changes to the objects to be updated are not possible.

All V2 updates are carried out in a separate LUW and not under the locks of the transaction that creates them. If your SAP System contains a work process for V2 updates, these are only carried out in this work process. If this is not the case, the V2 components are processed by a V1 update process.

All V1 modules of an update must be processed before the V2 modules.

Let us assume that a transaction makes planning changes to a material and balance sheet, and updates two sets of statistics.

Each of these changes is represented by means of an update module (call update function module) in the update request - the two planning changes by a V1 update module (time critical), and the statistical changes by a V2 update module (less critical). (The V1 modules have priority, although the V2 modules are usually also processed straight away).

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The Update Process

Purpose

Among other things, the update system is used to lighten the workload of the SAP transactions when time-consuming changes are made to the database. The changes are carried out asynchronously - usually with short delays in between - by special update work processes.

This is why the update system is widely used in SAP transactions (by almost every transaction that changes business data), although transactions can also change the data directly in the database.

Prerequisites

The application programmer decides whether, and if so, how, the update system is used for developing transactions. The different options open to the programmer are described in detail in the ABAP manual in the section entitled Update Techniques.

When you are working with the SAP update system, it is important to make sure that only insert, update and delete statements are executed in the update. The necessary data should, of course, be gathered together beforehand (using select and so on). Programming that has not been carefully thought through can result in poor system performance, and can, in certain cases, cause serious problems.

Process Flow

As illustrated in the graphic in Functional Description of Updates, at the end of a transaction COMMIT WORK and the update task are called; the dialog part of the SAP transaction is closed, and the update part of the SAP logical unit of work (LUW) is started. The following graphic illustrates the necessary actions and the sequence in which they execute the different work processes.

THANKS

MRUTYUN