What Aggregation Does
Use aggregation when you want:- Totals
- Averages
- Trends
- Comparisons across categories
Common Aggregations
- Sum — total revenue, total sales
- Average — average order value
- Count — number of records
- Min / Max — smallest or largest values
Example: “Total revenue by month”
Grouping Data
Grouping splits results by a category:- Revenue by region
- Orders by product
- Users by signup month
- Categories
- Time
- Multiple dimensions
Example: “Revenue by region and product category”
Filtering vs Grouping
| Action | Happens When |
|---|---|
| Filtering | Before aggregation |
| Grouping | During aggregation |
| Filtering results | After aggregation |
Examples:
- “Revenue from enterprise customers” → filter first
- “Regions with revenue over $1M” → aggregate first, then filter
Percentages & Ratios
Use aggregations to compute ratios:- Percentage of revenue by segment
- Share of total orders
- Conversion ratios
Example: “What percentage of revenue comes from enterprise customers?”
Segment & Benchmark Comparisons
Compare categories and identify outliers:- Compare segments: “Compare enterprise versus SMB customers on average order value”
- Compare to averages: “How does Product X compare to the category average?”
- Identify outliers: “Which salespeople are above the team average?”
Examples:
- “Enterprise vs SMB performance”
- “Compare product X to category average”
- “Customers whose spending is more than 2 standard deviations above normal”