diff --git a/samples/databases/wide-world-importers/wwi-integration-etl/README.md b/samples/databases/wide-world-importers/wwi-integration-etl/README.md index d08e7277..593d337f 100644 --- a/samples/databases/wide-world-importers/wwi-integration-etl/README.md +++ b/samples/databases/wide-world-importers/wwi-integration-etl/README.md @@ -34,26 +34,36 @@ To run this sample, you need the following prerequisites. 1. SQL Server 2016 (or higher). -2. SQL Server 2016 Integration Services. -3. Visual Studio 2015. +2. Visual Studio 2015. +3. SQL Server 2016 Integration Services. This needs to be installed on the same machine as Visual Studio to be able to build the project. ## Running the sample +1. Open the solution file WWI_Integration.sln in Visual Studio. + +2. Build the solution. + +3. TBD: running the ETL process + ## Sample details The ETL package WWI_Integration is used to migrate data from the WideWorldImporters database to the WideWorldImportersDW database as the data changes. The package is run periodically (most commonly daily). + The design of the package uses SSIS to orchestrate bulk T-SQL operations (rather than as separate transformations within SSIS) to ensure high performance. + Dimensions are loaded first, followed by Fact tables. The package can be re-run at any time after a failure. + The workflow is as follows: It starts with an expression task that works out the appropriate cutoff time. This time is the current time less a few seconds. (This is more robust than requesting data right to the current time). It then truncates any milliseconds from the time. -The main processing starts by populating the Date dimension table. It ensures that all dates for the current year have been populated in the table. -After this, a series of data flow tasks loads each dimension, then each fact. +The main processing starts by populating the Date dimension table. It ensures that all dates for the current year have been populated in the table. + +After this, a series of data flow tasks loads each dimension, then each fact.