Shulou(Shulou.com)06/01 Report--

This article is to share with you what the database locking strategy in Splash 4 HANA is, the editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

The new MM data model in S4 and the Insert-only feature of HANA allow parallel processing of material vouchers, which improves the related throughput. As a result, the application of database locks has also changed. These changes are described below (based on S 4 1610).

Key figure model and Account model

In SAP HANA 4 HANA, on-premise edition 1610, material valuation no longer requires an exclusive lock (exclusive locking), which includes all materials whose prices are controlled as "moving average prices" and for all special inventory types, because HANA is an Insert-only database, so it allows parallel processing of material vouchers.

Because in S/4HANA OP1610 and CE1608, the new MM-IM data model changes the old key figure model into the account model (and adds 53 additional columns to help with fast calculation / statistics), which allows for finer-grained delay quantity locking.

Here are examples of the Key figure model and the Account model

Key figure model:

Account model

For the Key figure model, locks must be added at the material and factory level. But through the Account model, locks can be added at materials, factories, storage locations, storage identifiers, and special storage identification levels (in principle, locks can be added at any level where inventory is defined in the new model). As a result, even when lock collisions are likely to occur in the past, they can now be processed in parallel.

Moving average price lock

When the movement of goods changes the inventory value (SALK3) and estimated inventory (LBKUM), the moving average price must be adjusted accordingly, which results in a V1-level update and an exclusive lock is required until the update ends. The change in quantity / value mainly comes from the external value brought about by the movement of goods (for example, from purchase orders). However, if the source of the change is only rounding differences, the moving average price will not be adjusted.

Lock when creating a batch (split evaluation)

Exclusive locks are required if material master data is created or changes are brought about by a cargo movement. If a split evaluation is used and a new batch must be created, cargo movement creates material master data.

Delayed shared locks for factories that do not allow negative inventory

HANA OP1610 4 and CE1608 introduce a new option to increase throughput. This option can be set in the configuration. For the deferred locking policy (late lock strategy), exclusive locks are no longer allowed, but deferred shared locks (late shared locks) are used, which makes the parallel processing of material vouchers a real reality.

Inventory checking is still feasible in this case, because all processes send their extraction to the lock server, which becomes the second storage of inventory changes (the first storage is the database). The data is calculated from the first and second storage.

Lock when the batch master data changes

Starting from HANA OP1610 4 and CE1608, for the collision rate of material voucher posting, for batch material line items, the batch lock only exists when the master data of the batch changes, such as the production date or best before date, and is different from the existing values in the database.

Optimization of On-the-fly calculations

As a result of on-the-fly calculation, aggregate quantity changes are stored in mixed and aggregate tables and become actual inventory data. This makes read access to these tables slower than Suite on HANA.

In order to turn the disadvantages of on-the-fly calculation into advantages, the following features will be introduced by Sdebar 4 HANA OP1610 and CE1608:

In the pre-read phase, only the material master data is read into the internal cache, which retrieves the data from the database through the pure material master data view.

In line item processing, the inventory quantity is read from the Account model of the database, and this only occurs if the inventory is reduced and negative inventory is prohibited.

Therefore, for Splash 4 HANA OP1610 and CE1608, the adjustment of the deferred locking policy allows parallel processing of material vouchers, while the strategy of reading inventory quantities from the database and inventory checking reduces the processing time of individual material vouchers. In short, the new version of the system reduces the processing time of material vouchers compared with the previous Sramp 4 HANA OP1511 and Suite on HANA.

Lock policy for factories that allow negative inventory

Under the delay lock strategy, no more locks are added.

There are no more inventory judgments from the database, and no inventory checks (under both locking strategies).

This is what the database locking strategy in Splash 4 HANA is. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.