Apache Impala
Apache Impala is an open-source, massively parallel processing (MPP) SQL query engine designed for high-performance, low-latency analytics on data stored in Apache Hadoop clusters. It enables users to run interactive SQL queries directly on data in HDFS, HBase, or cloud storage without requiring data movement or transformation. Impala integrates with the Hadoop ecosystem, leveraging Hive Metastore for metadata and supporting common file formats like Parquet, Avro, and ORC.
Developers should learn Apache Impala when they need to perform fast, interactive SQL queries on large datasets in Hadoop environments, such as for real-time business intelligence, data exploration, or ad-hoc analytics. It is particularly useful in scenarios where low-latency responses are critical, like dashboard reporting or iterative data analysis, as it avoids the overhead of MapReduce jobs. Use cases include financial analytics, log analysis, and customer behavior insights in big data platforms.