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eliminate_subqueries

polyglot_sql::optimizer::subquery

Function eliminate_subqueries 

Source 
pub fn eliminate_subqueries(expression: Expression) -> Expression
Expand description

Eliminate derived tables by converting them to CTEs.

This transformation rewrites derived tables (subqueries in FROM) as CTEs, which can deduplicate common subqueries and improve readability.

§Example

-- Before:
SELECT a FROM (SELECT * FROM x) AS y
-- After:
WITH y AS (SELECT * FROM x) SELECT a FROM y AS y

§Arguments

  • expression - The expression to optimize

§Returns

The optimized expression with subqueries converted to CTEs