2. OLTP vs OLAP and the Modern Data Stack
2.1 OLTP vs OLAP
Why. Running heavy reports on the live billing database locks cashiers during evening rush in Pune.
What. OLTP (online transaction processing) = many small writes (each bill). OLAP (online analytical processing) = fewer, heavier reads (month GST report).
How. Keep OLTP fast for billing. Copy data to an analytics store for OLAP-style questions.