HIVE:- Hive is an ETL (extract, transform, load) and data warehouse tool developed on the top of the Hadoop Distributed File System. In Hive, tables and databases are created first and then the data is loaded into these tables. Hive as data warehouse is designed only for managing and querying only the structured data that is stored in the table.
The main difference in HiveQL and SQL is the hive query executes on Hadoop's infrastructure rather than the traditional database. The Hive query execution is like a series of automatically generated Map Reduce jobs
By using Hive, we can achieve some peculiar functionality that is not achieved in the relational database. For a huge amount of data that is in peta-bytes, querying it and getting results in seconds is important, and hive does is quite efficient, it processes the query fast and produce results in seconds.