12. NoSQL Data Models

Episode 12 of 34 | System Design: From Fundamentals to Interview Mastery An original community-platform example compares key-value, document, wide-column and graph models through concrete lookup and update paths. It explains partition and clustering keys, embedding versus references, graph traversal costs, indexes, transaction boundaries, and model-specific failure behavior without claiming all NoSQL systems share the same guarantees. Original script, worked examples, diagrams and animation. Adapted educational presentation; no endorsement implied. Voice generated locally with the speaker's authorization. Chapters 0:00 Welcome and what we will cover 0:11 NoSQL is a family of models, not one guarantee 1:35 Key-value: make the lookup identity explicit 2:57 Documents: place related fields inside a bounded aggregate 4:21 Wide-column: design partitions around bounded queries 5:48 Graphs: make relationship traversal the central operation 7:15 Secondary indexes and duplicated views need maintenance 8:39 A data model does not decide every failure guarantee 10:06 Choose from the access pattern, then defend the cost 11:30 Recap, practice and thank you