For Delta in general having Delta cache accelerates data reads by creating copies of remote files in nodes’ local storage using a fast intermediate data format. The data is cached automatically whenever a file has to be fetched from a remote location. Successive reads of the same data are then performed locally, which results in significantly improved reading speed. And this can be useful even when performing merges where data has to be read.
https://docs.databricks.com/delta/optimizations/delta-cache.html#use-delta-caching
The recommended (and easiest) way to use Delta caching is to choose a Delta Cache Accelerated—
i3 or i3en series—worker type when you configure your cluster. Such workers are enabled and configured for Delta caching.
