WideWorldImportersDW database catalog

THIS TOPIC APPLIES TO: yesSQL ServernoAzure SQL DatabaseyesAzure SQL Data Warehouse yesParallel Data Warehouse

Explanations for the schemas, tables, and stored procedures in the WideWorldImportersDW database.

The WideWorldImportersDW database is used for data warehousing and analytical processing. The transactional data about sales and purchases is generated in the WideWorldImporters database, and loaded into the WideWorldImportersDW database using a daily ETL process.

The data in WideWorldImportersDW thus mirrors the data in WideWorldImporters, but the tables are organized differently. While WideWorldImporters has a traditional normalized schema, WideWorldImportersDW uses the star schema approach for its table design. Besides the fact and dimension tables, the database includes a number of staging tables that are used in the ETL process.

Schemas

The different types of tables are organized in three schemas.

Schema Description
Dimension Dimension tables.
Fact Fact tables.
Integration Staging tables and other objects needed for ETL.

Tables

The dimension and fact tables are listed below. The tables in the Integration schema are used only for the ETL process, and are not listed.

Dimension tables

WideWorldImportersDW has the following dimension tables. The description includes the relationship with the source tables in the WideWorldImporters database.

Table Source tables
City Application.Cities, Application.StateProvinces, Application.Countries.
Customer Sales.Customers, Sales.BuyingGroups, Sales.CustomerCategories.
Date New table with information about dates, including financial year (based on November 1st start for financial year).
Employee Application.People.
StockItem Warehouse.StockItems, Warehouse.Colors, Warehouse.PackageType.
Supplier Purchasing.Suppliers, Purchasing.SupplierCategories.
PaymentMethod Application.PaymentMethods.
TransactionType Application.TransactionTypes.

Fact tables

WideWorldImportersDW has the following fact tables. The description includes the relationship with the source tables in the WideWorldImporters database, as well as the classes of analytics/reporting queries each fact table is typically used with.

Table Source tables Sample Analytics
Order Sales.Orders and Sales.OrderLines Sales people, picker/packer productivity, and on time to pick orders. In addition, low stock situations leading to back orders.
Sale Sales.Invoices and Sales.InvoiceLines Sales dates, delivery dates, profitability over time, profitability by sales person.
Purchase Purchasing.PurchaseOrderLines Expected vs actual lead times
Transaction Sales.CustomerTransactions and Purchasing.SupplierTransactions Measuring issue dates vs finalization dates, and amounts.
Movement Warehouse.StockTransactions Movements over time.
Stock Holding Warehouse.StockItemHoldings On-hand stock levels and value.

Stored procedures

The stored procedures are used primarily for the ETL process and for configuration purposes.

Any extensions of the sample are encouraged to use the Reports schema for Reporting Services reports, and the PowerBI schema for Power-BI access.

Application Schema

These procedures are used to configure the sample. They are used to apply enterprise edition features to the standard edition version of the sample, add PolyBase, and reseed ETL.

Procedure Purpose
Configuration_ApplyPartitionedColumnstoreIndexing Applies both partitioning and columnstore indexes for fact tables.
Configuration_ConfigureForEnterpriseEdition Applies partitioning, columnstore indexing and in-memory.
Configuration_EnableInMemory Replaces the integration staging tables with SCHEMA_ONLY memory-optimized tables to improve ETL performance.
Configuration_ApplyPolybase Configures an external data source, file format, and table.
Configuration_PopulateLargeSaleTable Applies enterprise edition changes, then populates a larger amount of data for the 2012 calendar year as additional history.
Configuration_ReseedETL Removes existing data and restarts the ETL seeds. This allows for repopulating the OLAP database to match updated rows in the OLTP database.

Integration Schema

Procedures used in the ETL process fall in these categories:

  • Helper procedures for the ETL package - All Get* procedures.
  • Procedures used by the ETL package for migrating staged data into the DW tables - All Migrate* procedures.
  • PopulateDateDimensionForYear - Takes a year and ensures that all dates for that year are populated in the Dimension.Date table.

Sequences Schema

Procedures to configure the sequences in the database.

Procedure Purpose
ReseedAllSequences Calls the procedure ReseedSequenceBeyondTableValue for all sequences.
ReseedSequenceBeyondTableValue Used to reposition the next sequence value beyond the value in any table that uses the same sequence. (Like a DBCC CHECKIDENT for identity columns equivalent for sequences but across potentially multiple tables.)