# name: test/optimizer/statistics/statistics_null_comparison.test
# description: Statistics propagation with comparisons and null values
# group: [statistics]

statement ok
CREATE TABLE integers AS SELECT * FROM (VALUES (10, 1), (20, 2), (30, NULL)) tbl(i, j);

statement ok
CREATE TABLE integers2 AS SELECT * FROM (VALUES (1), (2), (NULL)) tbl(i);

statement ok
CREATE TABLE t1 AS SELECT * FROM (VALUES (1)) tbl(c0);

statement ok
CREATE TABLE t2 AS SELECT * FROM (VALUES (NULL)) tbl(c0);

statement ok
PRAGMA explain_output = OPTIMIZED_ONLY;

# this is statically false, but there are null values NOT in a filter, so we can't optimize it away
# instead the comparison is replaced by a CONSTANT OR NULL
query II
EXPLAIN SELECT i=j FROM integers ORDER BY i;
----
logical_opt	<REGEX>:.*constant_or_null.*

# if we put the same expression in a where clause, however, we CAN prune it
query II
EXPLAIN SELECT * FROM integers WHERE i=j ORDER BY i;
----
logical_opt	<!REGEX>:.*constant_or_null.*

# this is statically true, but there are null values, so we can't optimize it away
query II
EXPLAIN SELECT i>j FROM integers ORDER BY i;
----
logical_opt	<REGEX>:.*constant_or_null.*

# if we put it in the where clause, we STILL can't prune it
query II
EXPLAIN SELECT * FROM integers WHERE i>j ORDER BY i;
----
logical_opt	<REGEX>:.*constant_or_null.*

# now verify that the results are correct
query I
SELECT i=j FROM integers ORDER BY i;
----
0
0
NULL

query II
SELECT * FROM integers WHERE i=j ORDER BY i;
----

query I
SELECT j=i FROM integers ORDER BY i;
----
0
0
NULL

query I
SELECT i>j FROM integers ORDER BY i;
----
1
1
NULL

query II
SELECT * FROM integers WHERE i>j ORDER BY i;
----
10	1
20	2

# relate issue 17338
query II
SELECT * FROM t1 INNER JOIN t2 ON ((t2.c0)>=(t2.c0));
----

statement ok
INSERT INTO t2 VALUES(1);

# t2.c0>=t2.c0 means always true or null which is equals to is not null
query II
EXPLAIN SELECT * FROM t1 INNER JOIN t2 ON ((t2.c0)>=(t2.c0));
----
logical_opt	<REGEX>:.*IS NOT NULL.*

query II
SELECT * FROM t1 INNER JOIN t2 ON ((t2.c0)>=(t2.c0));
----
1	1