Apache Hive is a data warehousing and SQL-like query language for Hadoop. It provides a way to structure and query data stored in the Hadoop Distributed File System (HDFS) or other storage systems integrated with Hadoop, such as Amazon S3 or Azure Data Lake Storage.
Here are the main components of Hive:
- HiveQL: HiveQL is the query language of Hive, which is similar to SQL and enables users to query and manage large datasets stored in Hadoop.
- Hive Metastore: The Hive metastore is a central repository for storing metadata about Hive tables and partitions. It stores information about the structure and properties of the data in Hive tables, such as the data types and names of columns, as well as the location of the data stored in the Hadoop filesystem.
- Hive Driver: The Hive driver receives queries written in HiveQL from the user, converts them into MapReduce or Spark jobs, and then submits them to the Hadoop cluster for execution.
- Hive Server: The Hive server is a service that listens for client connections and processes client requests, such as submitting HiveQL queries. It provides a Thrift interface, which enables clients written in any language to connect to the Hive server and submit queries.
- Hive Clients: Hive clients are applications that connect to the Hive server and submit HiveQL queries. These can include command-line tools, such as Hive shell, or programming interfaces, such as JDBC or ODBC.