n this lecture we cover Online Analytical Processing (OLAP) — the analytical layer that sits on top of a data warehouse and enables fast, interactive, multidimensional analysis for business decision-making.
We start with a quick recap of how data models, star schemas, and ETL pipelines from previous lectures connect directly to OLAP. From there, we build up the concept of the data cube from first principles — showing how fact and dimension tables transform into a three-dimensional structure — and then explore how analysts use that cube to answer complex business questions.
Topics covered:
— What OLAP is and why organisations use it
— MOLAP vs ROLAP: pre-computed cubes vs relational query engines
— The data cube: dimensions, measures, and cells
— The five core OLAP operations: Slice, Dice, Drill-Down, Roll-Up, and Pivot
— SQL query examples for every operation, with step-by-step explanations
— MDX query basics for MOLAP systems
This lecture is part of SENG 31333: Business Intelligence and Management Support Systems.
