# name: test/optimizer/cte_inlining.test
# description: Test the CTE Inlining optimizer
# group: [optimizer]

statement ok
SET default_null_order='nulls_first';


statement ok
create table a(i integer);

statement ok
insert into a values (42);

statement ok
PRAGMA explain_output = OPTIMIZED_ONLY

# in alternative verify mode, CTEs may not be inlined
require no_alternative_verify

# single reference to CTE, should be inlined
query II
explain with cte1 as (Select i as j from a) select * from cte1;
----
logical_opt	<!REGEX>:.*CTE.*

# multiple references to CTE, not inlined by default, but can be forced
query II
explain with cte1 as NOT MATERIALIZED (Select i as j from a) select * from cte1;
----
logical_opt	<!REGEX>:.*CTE.*

# Test chained CTEs
query II
explain
with
  cte1 as (select i as j from a),
  cte2 as (select * from cte1)
select * from cte2;
----
logical_opt	<!REGEX>:.*cte1.*

# Test complex case with both materialized and not materialized CTEs
query II
explain
with
  cte1 as MATERIALIZED (select i as j from a),
  cte2 as NOT MATERIALIZED (select * from cte1)
select * from cte2;
----
logical_opt	<REGEX>:.*CTE.*

# Test non-referenced CTE
query II
explain
with
  cte1 as (select i as j from a)
select * from a;
----
logical_opt	<!REGEX>:.*CTE.*