Siebel Customer-Centric Enterprise Warehouse Installation and Configuration Guide > Configuring Common Components of the Siebel Customer-Centric Enterprise Warehouse > Filtering and Deleting Records >

About Primary Extract and Delete Mappings Process

Before you decide to enable primary extract and delete sessions, it is important to understand their function within the Siebel Customer-Centric Enterprise Warehouse. Primary extract and delete mappings allow your analytics system to determine which records are removed from the source system by comparing primary extract staging tables with the most current Siebel Customer-Centric Enterprise Warehouse table.

The primary extract mappings perform a full extract of the primary keys from the source system. Although many rows are generated from this extract, the data only extracts the Key ID and Source ID information from the source table. The primary extract mappings load these two columns into staging tables that are marked with a *_PE suffix.

Figure 23 provides an example of the beginning of the extract process. It shows the sequence of events over a two day period during which the information in the source table has changed. On day one, the data is extracted from a source table and loaded into the Siebel Customer-Centric Enterprise Warehouse table. On day two, Sales Order number three is deleted and a new sales order is received, creating a disparity between the Sales Order information in the two tables.

Figure 23. Changing Sales Order Information

Figure 24 shows the primary extract and delete process that occurs when day two's information is extracted and loaded into the Siebel Customer-Centric Enterprise Warehouse from the source. The initial extract brings record four into the Siebel Customer-Centric Enterprise Warehouse. Then, using a primary extract mapping, the system extracts the Key IDs and the Source IDs from the source table and loads them into a primary extract staging table.

The extract mapping compares the keys in the primary extract staging table with the keys in the most current the Siebel Customer-Centric Enterprise Warehouse table. It looks for records that exist in the Siebel Customer-Centric Enterprise Warehouse but do not exist in the staging table (in the preceding example, record three), and sets the delete flag to Y in the Source Adapter mapplet, causing an eventual deletion in the Siebel Customer-Centric Enterprise Warehouse.

The extract mapping also looks for any new records that have been added to the source, and which do not already exist in the Siebel Customer-Centric Enterprise Warehouse; in this case, record four. Based on the information in the staging table, Sales Order number three is physically deleted from Siebel Customer-Centric Enterprise Warehouse, as shown in Figure 24. When the extract and load mappings run, the new sales order is added to the warehouse.

Figure 24. Primary Extract and Delete Mappings