Ralph Kimball
Data warehouse architect who developed the dimensional modeling methodology and the Kimball bottom-up approach to DWH design.
Last updated: 2026-04-12
Overview
Ralph Kimball is the originator of dimensional modeling — the star schema-based approach to designing data warehouses that became the dominant methodology for analytics and business intelligence. His work at Stanford, Metaphor Computer Systems, and later the Kimball Group defined how most modern data warehouses are built.
His approach is often called “bottom-up” because it advocates building subject-area data marts first, then integrating them through conformed dimensions, rather than designing a monolithic enterprise warehouse before building any user-facing value.
Key Contributions
- Dimensional modeling (fact tables + dimension tables + star schema)
- Conformed dimensions: The mechanism for integrating across business processes without a single monolithic model
- SCD types 0–3: The original slowly-changing dimension classification. See slowly-changing-dimensions
- The Data Warehouse Toolkit (book): The foundational reference for dimensional modeling practitioners
- The Kimball Group: Consulting and publishing firm that extended and documented the methodology
Key Concepts
- dimensional-modeling — his core methodology
- star-schema — the physical schema form
- fact-table-types — taxonomy of fact table patterns
- slowly-changing-dimensions — SCD types 0–3 defined by Kimball
Kimball vs. Inmon
See dimensional-modeling for the full comparison. Short version: Kimball = bottom-up, dimensional, faster time-to-value; bill-inmon = top-down, normalized, enterprise consistency first.
Sources
- Dimensional Modeling — Joakim Dalby — added 2026-04-12