Basic Concepts

Client
Users can access the server from the client through Java APIs and Thrift APIs to perform Hive-related operations. The Hive client in this document refers to the Hive client installation directory, which contains sample codes for Hive access using Java APIs.
HiveQL
Similar to SQL
HCatalog
HCatalog is a table information management layer created based on Hive metadata and incorporates DDL commands of Hive. HCatalog provides read/write APIs for MapReduce and offers a Hive command line interface (CLI) for defining data and querying metadata. The Hive HCatalog function enables Hive and MapReduce development personnel to share metadata, preventing intermediate conversion and adjustment and improving the data processing efficiency.
WebHCat
WebHCat running users use REST APIs to run Hive DDL commands, submit MapReduce tasks, query MapReduce task execution results, and perform other operations.