extraction transformation load - ETL, Schemes and Mind Maps of Data Warehousing

Download extraction transformation load - ETL and more Schemes and Mind Maps Data Warehousing in PDF only on Docsity! ETL TESTING What is Full Load: When we are loading the data for first time, all the set of records will be loaded in DWH. Incremental Load: It is a method to capture on the newly created or updated record. Based upon the flag or Date this load will be performed. Refresh or Reload Load: The table will be truncated and data will be loaded again. What is ODS? ODS: ODS is also a similar small DWH which will help analyst to analysis the business. It will have data for less number of days. Generally it will be around 30-45 days. Like DWH here also surrogate keys will be generated, error and reject handling will be done. Operational Data store is used by many organizations for analysis purpose as well as for data backup and data recovery. Data stored in ODS is usually in Normalized form as in transactional DBs. While in DWH data will be denormalized. ODS is actually a replica of Transactional Database, colleting two or more Business functions data. Ex ODS may store CRM as well as ERP data. What is ETL process? ETL is extraction, transforming and loading processes, we will extract the data from the source systems and apply the business rules on it and then load it in the target database (DWH). What is a staging area? Do we need it? What is the purpose of a staging area? Staging is a temporary storage area where all the data manipulation (cleansing, merging, scrubbing, transformations, etc.) takes place