7. Star Schema — The Key to Gold Performance

Star schema improves everything downstream — SQL endpoint performance, Direct Lake performance, BI performance, and query simplicity.

Components

• Fact tables
• Dimension tables
• Surrogate keys

Star schema is mandatory for Gold. Don’t expose wide flat tables to Power BI — model them properly.

8. Aggregation Tables — Boost BI Performance

Aggregation tables pre‑compute totals, counts, averages, and KPIs so Power BI doesn’t have to scan the full fact table on every query.

Benefits

• Faster dashboards
• Lower compute cost
• Better Direct Lake performance

Aggregation tables are essential for enterprise BI at scale.

9. Direct Lake Optimization

Best Practices

• Use Gold tables — never point Direct Lake at Bronze or Silver
• Partition fact tables by date
• Apply Z‑Order on frequently filtered columns
• Run compaction regularly
• Use star schema
• Use aggregation tables for high-traffic measures

Direct Lake performance depends entirely on Delta optimization. A poorly optimized Gold table means slow dashboards regardless of compute capacity.