Techniques to extract and flatten hierarchies

摘要

Techniques for extracting hierarchical data stored in multiple records, flattening the hierarchical data, and storing the flattened data in a data warehouse. The data source may be an online transaction processing (OLTP) system that is designed to perform transaction processing and that stores hierarchy data in the form of multiple parent-child relationship records. The hierarchy data extracted from the data source is flattened and stored in a flattened form in a target system such as a data warehouse. A database function such as the SYS_CONNECT_BY_PATH may be used as part of the flattening process.