Reviewed by Aditya Kumar · Last reviewed 2026-03-24
**Architectural Logic**: OLTP and OLAP solve orthogonal problems—transactional integrity vs analytical throughput—with different scaling and cost models. **OLTP**: Optimized for high-throughput, low-latency writes; ACID; normalized schemas; row-level locking. Powers core...
This medium-level SQL question appears frequently in data engineering interviews at companies like Goldman Sachs. While less common, it tests deeper understanding that distinguishes strong candidates. Mastering the underlying concepts (bigquery, etl, partition) will help you answer variations of this question confidently.
Break this problem into components. Identify the core trade-offs involved, then walk the interviewer through your reasoning step by step. Demonstrate awareness of edge cases and production considerations - this is what separates good answers from great ones.
Architectural Logic: OLTP and OLAP solve orthogonal problems—transactional integrity vs analytical throughput—with different scaling and cost models. OLTP: Optimized for high-throughput, low-latency writes; ACID; normalized schemas; row-level locking. Powers core banking, trade execution. Scales vertically and via read replicas; write path is critical. OLAP: Denormalized star/snowflake; columnar storage; batch-oriented; powers risk aggregation, P&L, regulatory reporting. Scales horizontally; scan-optimized. Why Separation: Mixing OLTP writes with analytical scans degrades both—lock contention, cache pollution. Scalability Trade-off: OLTP scales by sharding and replication; OLAP by adding compute nodes and partitioning. Cost: OLTP = always-on baseline; OLAP can scale-to-zero (BigQuery, Snowflake). Replicate via CDC or batch ETL; never run analytics on production OLTP.
Red Flag: Proposing analytics queries directly on the OLTP database—guarantees production impact. Pro-Move: Reference CDC (Debezium, Fivetran) or batch sync patterns with clear SLAs for analytics freshness.
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According to DataEngPrep.tech, this is one of the most frequently asked SQL interview questions, reported at 1 company. DataEngPrep.tech maintains an editor-reviewed database of 1,863 data engineering interview questions across 7 categories.