Which data format is most efficient for columnar storage and analytics workloads?
- CSV
- JSON
- Parquet
- XML
Answer: Parquet
Parquet is a columnar storage format optimized for analytics: efficient compression, predicate pushdown, and schema evolution. Reduces I/O by reading only required columns. Used in Spark, Hive, Presto. CSV/JSON are row-oriented; XML is verbose. Critical for big data engineering questions.