Hive CLI (Command Line Interface) is a tool provided by Apache Hive, which is a data warehouse infrastructure built on top of Hadoop. The Hive CLI allows users to interact with Hive and execute HiveQL (Hive Query Language) commands directly from the command line.
Here’s a breakdown of some key points about the Hive CLI:
- Purpose: The Hive CLI is designed to provide a command-line interface for users to interact with Hive. It allows users to submit HiveQL queries, manage databases, tables, and perform various administrative tasks related to Hive.
- Functionality: Users can use the Hive CLI to perform a wide range of tasks such as creating, dropping, and altering databases and tables, querying data using HiveQL, managing partitions, and executing Hive scripts stored in files.
- HiveQL: HiveQL is a SQL-like language used to query and manage data stored in Hive. The Hive CLI allows users to write and execute HiveQL commands directly from the command line interface.
- Integration with Hadoop: Hive is tightly integrated with the Hadoop ecosystem. It leverages Hadoop’s distributed file system (HDFS) for storage and MapReduce for processing large datasets. The Hive CLI interacts with these components seamlessly, enabling users to query and analyze large datasets stored in Hadoop.
- Interactive and Scripting Mode: The Hive CLI supports both interactive and scripting modes. In interactive mode, users can enter commands one at a time and receive immediate feedback. In scripting mode, users can execute a series of commands stored in a script file.
- Configuration and Customization: Users can customize the behavior of the Hive CLI by configuring various parameters such as Hive server connection settings, authentication mechanisms, and logging options.
- Documentation: The Apache Hive project provides extensive documentation for the Hive CLI, including a Language Manual that covers the syntax and semantics of HiveQL commands supported by the CLI. The documentation also includes examples, best practices, and troubleshooting tips for using the Hive CLI effectively.
hive Command Examples
1. Start a Hive interactive shell:
2. Run HiveQL:
# hive -e "[hiveql_query]"
3. Run a HiveQL file with a variable substitution:
# hive --define [key]=[value] -f [path/to/file.sql]
4. Run a HiveQL with HiveConfig (e.g. mapred.reduce.tasks=32):
# hive --hiveconf [conf_name]=[conf_value]
Overall, the Hive CLI is a powerful tool for interacting with Hive and performing data analysis tasks on large-scale datasets stored in Hadoop. It provides a flexible and intuitive interface for users to query and manage data using HiveQL commands from the command line.