@Evolving public interface SupportsPushDownRequiredColumns extends ScanBuilder
ScanBuilder. Data sources can implement this interface to push down required columns to the data source and only read these columns during scan to reduce the size of the data to be read.
void pruneColumns(StructType requiredSchema)
Implementation should try its best to prune the unnecessary columns or nested fields, but it's also OK to do the pruning partially, e.g., a data source may not be able to prune nested fields, and only prune top-level columns.
Scan.readSchema() implementation should take care of the column
pruning applied here.