How to use the command 'odps' (with examples)
The ‘odps’ command is the command-line tool for Aliyun ODPS (Open Data Processing Service). It allows users to interact with their ODPS projects, tables, partitions, and perform various operations through the command line.
Use case 1: Start the command-line with a custom configuration file
Code:
odpscmd --config=odps_config.ini
Motivation: In some cases, users may need to start the ‘odps’ command-line with a custom configuration file. This is particularly useful when the default configurations do not meet the requirements of the project or when specific settings need to be applied.
Explanation:
odpscmd: The command to start the ‘odps’ command-line tool.--config=odps_config.ini: Specifies the path to the custom configuration file.
Example output:
ODPS: command line tool for Alibaba Cloud Open Data Processing Service
Please input access_id: ***********
Please input access_key: ***********
login success
Use case 2: Switch current project
Code:
use project_name;
Motivation: Users often work on multiple projects within an ODPS account. By switching the current project, users can easily navigate between different projects and perform operations on the desired project.
Explanation:
use: The keyword to switch the current project.project_name: The name of the project to switch to.
Example output:
Project is switched to project_name.
Use case 3: Show tables in the current project
Code:
show tables;
Motivation: When working within a project, it is important to have a list of all the tables available. The ‘show tables’ command helps users get the list of tables in the current project.
Explanation:
show tables: The command to list all the tables in the current project.
Example output:
+----------------------+
| Tables |
+----------------------+
| table1 |
| table2 |
| table3 |
+----------------------+
Use case 4: Describe a table
Code:
desc table_name;
Motivation: Understanding the structure and metadata of a table is crucial for data analysis and manipulation. The ‘desc’ command provides users with detailed information about the specified table.
Explanation:
desc: The command to describe a table.table_name: The name of the table to describe.
Example output:
+---------------+------------+---------+
| Column | Type | Comment |
+---------------+------------+---------+
| column1 | string | |
| column2 | bigint | |
| column3 | double | |
+---------------+------------+---------+
Use case 5: Show table partitions
Code:
show partitions table_name;
Motivation: A table in ODPS can be partitioned based on specific fields. To understand the partitioning scheme and list all the available partitions, the ‘show partitions’ command is used.
Explanation:
show partitions: The command to list all the partitions of a table.table_name: The name of the table to show partitions for.
Example output:
+----------------+
| Partitions |
+----------------+
| partition1 |
| partition2 |
| partition3 |
+----------------+
Use case 6: Describe a partition
Code:
desc table_name partition (partition_spec);
Motivation: When a table is partitioned, it is useful to understand the metadata and structure of a specific partition. The ‘desc’ command can be used to describe a specific partition of a table.
Explanation:
desc: The command to describe a partition of a table.table_name: The name of the table that contains the partition.partition_spec: The specification of the partition, which can include partition key-value pairs.
Example output:
+---------------+------------+---------+
| Column | Type | Comment |
+---------------+------------+---------+
| column1 | string | |
| column2 | bigint | |
| column3 | double | |
+---------------+------------+---------+
Conclusion:
The ‘odps’ command-line tool provides a set of powerful functionalities to interact with Aliyun ODPS. By using the various subcommands, users can start the command-line with a custom configuration file, switch between projects, list tables, describe tables, show partitions, and describe partitions. This is essential for managing and analyzing data within an Aliyun ODPS environment.
