How to use the command 'odps table' (with examples)
This article explains how to use the ‘odps table’ command in ODPS (Open Data Processing Service) with various use cases.
Description
The ‘odps table’ command allows users to create and modify tables in ODPS. It is a command-line interface for managing tables and provides various functionalities such as creating tables, adding partitions, dropping partitions, and deleting tables.
Use case 1: Create a table with partition and lifecycle
Code:
odps table create table_name (col type) partitioned by (col type) lifecycle days;
Motivation: The motivation for using this example is to create a table with a specific partition and lifecycle configuration. Partitioning tables allows for better organization and management of data, while the lifecycle configuration specifies the number of days that the table data will be preserved.
Explanation:
create table table_name: This is the command to create a table named ’table_name’.(col type): This specifies the columns and their respective data types for the table.partitioned by (col type): This specifies the column to use for partitioning the table.lifecycle days: This specifies the number of days to preserve the data in the table.
Example output: The command will create a table named ’table_name’ with the specified columns and partitioning. The table’s data will be preserved for the specified number of days.
Use case 2: Create a table based on the definition of another table
Code:
odps table create table_name like another_table;
Motivation: The motivation for using this example is to create a new table with the same definition as an existing table. This can be useful when creating multiple tables with similar structures.
Explanation:
create table table_name: This is the command to create a table named ’table_name’.like another_table: This specifies that the new table should be created based on the definition of ‘another_table’.
Example output: The command will create a new table named ’table_name’ with the same structure as ‘another_table’.
Use case 3: Add partition to a table
Code:
odps table alter table_name add partition (partition_spec);
Motivation: The motivation for using this example is to add a new partition to an existing table. This can be helpful when new data needs to be organized and managed separately.
Explanation:
alter table table_name: This is the command to modify an existing table named ’table_name'.add partition (partition_spec): This specifies the partition to be added to the table.
Example output: The command will add a new partition to the specified table.
Use case 4: Delete partition from a table
Code:
odps table alter table_name drop partition (partition_spec);
Motivation: The motivation for using this example is to remove a partition from an existing table. This can be useful when old or unnecessary data needs to be deleted.
Explanation:
alter table table_name: This is the command to modify an existing table named ’table_name'.drop partition (partition_spec): This specifies the partition to be dropped from the table.
Example output: The command will delete the specified partition from the table.
Use case 5: Delete table
Code:
odps table drop table_name;
Motivation: The motivation for using this example is to delete an existing table. This can be necessary when the table is no longer needed or when there is a need to free up resources.
Explanation:
drop table table_name: This is the command to delete an existing table named ’table_name'.
Example output: The command will delete the specified table.
Conclusion
The ‘odps table’ command in ODPS provides a convenient way to manage tables. It allows users to create tables with specific configurations, replicate existing tables, add and delete partitions, and delete tables altogether. By understanding these various use cases, users can effectively utilize this command to meet their data management needs in ODPS.
