We all know ‘garbage in, garbage out’. But what happens when the data provider (source system) realizes that they have provided incorrect data to the data warehouse? And now they want to correct the mistake by providing you new data! By then ETL has already loaded the data. The data is inserted, updated & deleted! Simple inserts is easy, but what about integrated data because of updates? How do you recover from such situation? Can you actually recover? What should be the ETL strategy?
Has your Data warehouse Architect/Manager/ETL Lead come up with an ETL Strategy?
NOTE: This post is applicable to all etl tools or databases like Informatica, DataStage, Syncsort DMExpress, Sunopsis or Oracle, Sybase, SQL Server Integration Services (SSIS)/DTS, Ab Initio, MS SQL Server, RDB, Teradata, etc.