12. Data Hierarchies and Groups
12.1 What Is a Hierarchy?
A hierarchy (श्रेणीरचना) is an ordered set of columns from the same table, from general to detailed. Users can drill down from a higher level to a lower one (Module 16).
| Hierarchy | Levels | Example path |
|---|---|---|
| Date (Date table) | Year › Quarter › Month › Day | 2025 › Q4 › October › 20 |
| Location (DarkStore) | State › City › Area › Store Name | Maharashtra › Pune › Kothrud › Blinkit Kothrud Hub |
| Product (Product) | Category › Sub Category › Product Name | Fruits & Vegetables › Fresh Fruits › Nashik Grapes 500 g |
Simple bhashet sangaycha tar, levels must be in one table. That is one reason why dimension tables such as DarkStore contain State, City and Area together (star schema, Module 11).
Ravindra Bagale's Tip
Friends, many students confuse a hierarchy with a group. A hierarchy is a drill path (State › City › Area › Store). A group combines values into buckets (Pune + Solapur = West). Use the right tool, and remember that you can combine them, for example Region › City.
Ravindra Bagale's Tip – मराठी
मित्रांनो, बरेच students hierarchy आणि group मध्ये गल्लत करतात. Hierarchy म्हणजे drill path (State › City › Area › Store). Group म्हणजे values एकत्र करून buckets बनवणं (Pune + Solapur = West). योग्य tool वापरा, आणि लक्षात ठेवा की दोन्ही एकत्र वापरता येतात, उदाहरणार्थ Region › City.
Ravindra Bagale's Tip – हिंदी
दोस्तों, बहुत से students hierarchy और group को आपस में मिला देते हैं. Hierarchy एक drill path है (State › City › Area › Store). Group values को मिलाकर buckets बनाता है (Pune + Solapur = West). सही tool इस्तेमाल करो, और याद रखो कि दोनों को साथ में इस्तेमाल कर सकते हो, जैसे Region › City.