What is predicate pushdown?

Predicate pushdown refers to applying filtering as close as possible to the data-access stage so fewer rows need to flow through later operators.

SQL Server's optimizer can often push eligible predicates into scans, seeks, joins, columnstore processing, or other operators automatically. This reduces I/O and CPU when the storage engine can eliminate rows earlier.

Whether pushdown occurs depends on query structure, data types, expressions, storage technology, and optimizer capabilities.