Module pushdown_predicates 

Predicate pushdown into subqueries and JOINs Predicate Pushdown Module

This module provides functionality for pushing WHERE predicates down into subqueries and JOINs for better query performance.

When a predicate in the outer query only references columns from a subquery, it can be pushed down into that subquery’s WHERE clause to filter data earlier.

Ported from sqlglot’s optimizer/pushdown_predicates.py

Functions

make_true

Create a TRUE literal expression

pushdown_predicates

Rewrite SQL AST to pushdown predicates in FROMs and JOINs.

replace_aliases

Replace aliases in a predicate with the original expressions