This topic describes how Index Cache works, its use cases, and how to configure it. For large datasets where disk capacity is too limited for a full data cache, Index Cache boosts query performance by caching only the index data.
Introduction
If your cache disk is too small for all data, or if a full data cache would use too much disk space, disable Data Cache and enable only Index Cache. This method caches only index data, significantly improving query performance with minimal disk overhead.
Limitations
Supported versions: v3.3.13 and later. This feature is enabled by default.
This feature is limited to internal tables in the Default Catalog on clusters with a separation of storage and compute architecture.
Parameters
Configure Index Cache by adding the following parameters to your compute group configuration in the Alibaba Cloud console:
Parameter | Default | Description |
|
| Enables or disables Index Cache. To disable the feature, set this parameter to |
|
| Specifies the percentage of disk capacity that Index Cache can use. |
On clusters with a separation of storage and compute that use both internal and data lake external tables, ensure the combined size of Index Cache and Data Cache does not exceed total disk capacity.
Disable Index Cache
In your compute group configuration on the Alibaba Cloud console, set starlet_enable_index_cache to false:
starlet_enable_index_cache = false