DROP FUNCTION IF EXISTS f1, dbo.f1_inline
GO

CREATE FUNCTION dbo.f1_inline (@a INT)
RETURNS table
WITH SCHEMABINDING
as
return select @a as a;
go

CREATE FUNCTION dbo.f1 (@a INT)
RETURNS INT
WITH SCHEMABINDING
AS BEGIN
    RETURN (select a from dbo.f1_inline(@a))
END
GO

DROP TABLE IF EXISTS t1

create table t1 (a int);
update statistics t1 with rowcount = 10000000, pagecount = 1000000;

set statistics xml on;

SELECT COUNT(1)
FROM t1
WHERE dbo.f1(a) = 1
OPTION(QUERYTRACEON 8649)

SELECT COUNT(1)
FROM t1
WHERE dbo.f1(a) = 1
OPTION(USE HINT('ENABLE_PARALLEL_PLAN_PREFERENCE'));

SELECT COUNT(1)
FROM t1 cross apply
dbo.f1_inline(t1.a) a
WHERE a.a = 1
OPTION(QUERYTRACEON 8649)

SELECT COUNT(1)
FROM t1 cross apply
dbo.f1_inline(t1.a) a
WHERE a.a = 1
OPTION(USE HINT('ENABLE_PARALLEL_PLAN_PREFERENCE'));

set statistics xml off;
go

DROP FUNCTION IF EXISTS f1, dbo.f1_inline
DROP TABLE IF EXISTS t1