Predicate Pushdown

Concepts: paColumnarVsRow

What They Want to Hear 'Predicate pushdown pushes the WHERE clause to the storage layer. In Parquet, each row group stores min/max statistics per column. If the query asks for revenue > 1000 and a row group's max revenue is 500, the entire row group is skipped without reading it. Combined with partition pruning, this can skip 99%+ of the data.' The key insight they are testing: pushdown works at TWO levels: partition pruning (skip folders) and row group pruning (skip chunks within files).