The ReduceLocalInventory component, which usually appears in the Inventory stage of an order processing pipeline, deducts the quantity of an item being purchased from the column in the database that stores the total number of the item available in inventory.
This component is used for compatibility with Commerce Server version 2.0 sites, in which the database connection is provided by the Content object in the Pipe Context. Commerce Server 3.0 sites should use the SQLItemADO component. The ReduceLocalInventory component does not support MTS transactions, therefore you should not include it in an MtsTxOrderPipeline object.