ETL Oracle: from 4 hours to 25 minutes with staging tables, MERGE and parallel DML
A real Oracle 19c Data Warehouse case: how row-by-row inserts, missing indexes, and frequent COMMITs were killing a nightly ETL batch window.
Etl
3 tagged articles
Data Warehouse
Data Warehouse
Ragged hierarchies: when the client has no parent and the group has no grandparent
Ragged hierarchy in the data warehouse: balancing unbalanced trees with the self-parenting technique. Correct drill-down on customers and groups.
Data Warehouse
SCD Type 2: the history the business didn't know it needed
SCD Type 2 in the data warehouse: historicising dimensions with surrogate keys and validity dates. Real case: a customer dimension that evolves over time.