greenplum Redistribute Motion
时间: 2023-12-02 07:04:31 浏览: 47
Greenplum Redistribute Motion is a step in the query execution plan of Greenplum Database, which is an open source massively parallel processing (MPP) database management system designed for analytics and data warehousing.
In Greenplum, data is distributed across multiple segments, and the Redistribute Motion step is used to shuffle data between segments based on a specified distribution key. This step is commonly used to optimize join operations, where data from two tables needs to be combined based on a common key.
During the Redistribute Motion step, Greenplum redistributes the data based on the distribution key to ensure that data with the same key values are co-located on the same segment. This improves query performance by reducing the amount of data that needs to be transferred between segments during join operations.