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Ragged hierarchies: when the client has no parent and the group has no grandparent
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.

20 January 2026 12 min
SCD Type 2: the history the business didn't know it needed
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.

11 November 2025 13 min