Overview of Apache Hive
masterApache Hive is a data warehouse software built on top of Apache Hadoop that facilitates reading, writing, and managing large datasets using SQL. It is designed for large-scale data warehousing tasks like ETL, reporting, and data analysis rather than online transaction processing (OLTP).
Key capabilities include:
- SQL Access: Enables data warehousing via SQL, including OLAP functions, subqueries, and common table expressions.
- Data Structuring: Imposes structure on various data formats.
- Storage Integration: Accesses files in Apache HDFS or other systems like Apache HBase.
- Query Execution: Uses the Apache Tez framework for interactive query execution with reduced overhead compared to MapReduce.
- Extensibility: Supports user-defined functions (UDFs), user-defined aggregates (UDAFs), and user-defined table functions (UDTFs).