The feature signatures of large spatio-temporal objects are used in Ganos to optimize the storage of these objects. This storage optimization feature allows you to store the metadata of these objects in-row and store the entity data of these objects off-row. This increases processing performance and reduces I/O overhead in scenarios such as spatio-temporal index creation and spatial joins.
Configure the storage optimization feature
After you connect to your PolarDB cluster, you can enable or disable the storage optimization feature by using a Grand Unified Configuration (GUC) parameter. By default, the storage optimization feature is disabled.
- To enable the storage optimization feature, run the following command:
set polar_enable_storage_partial = true;
- To disable the storage optimization feature, run the following command:
set polar_enable_storage_partial = false;
Configure the threshold for storage optimization
After you enable the storage optimization feature, PolarDB implements in-row storage and off-row storage on a large spatio-temporal object only when the number of bytes for the object exceeds the value of the
The value of the
polar_partial_external_threshold parameter ranges from 1000 to 8000. The default value is 2000. Before you create a table, you can reconfigure this parameter. Example:
set polar_partial_external_threshold = 3000;