Function expression_planner

src/backend/optimizer/plan/planner.c:6747–6762

* expression_planner * Perform planner's transformations on a standalone expression. * * Various utility commands need to evaluate expressions that are not part * of a plannable query. They can do so using the executor's regular * expression-execution machinery, but first the expression has to be fed * through here to transform it from parser output to something executable. * * Currently

 * context; beware that this can leak a lot of additional stuff there, too.
 */
Expr *
expression_planner(Expr *expr)
{
	Node	   *result;

	/*
	 * Convert named-argument function calls, insert default arguments and
	 * simplify constant subexprs
	 */
	result = eval_const_expressions(NULL, (Node *) expr);

	/* Fill in opfuncid values if missing */
	fix_opfuncids(result);

	return (Expr *) result;
}

/*
 * expression_planner_with_deps