# name: test/optimizer/statistics/statistics_coalesce.test
# description: Test statistics propagation in COALESCE expression
# group: [statistics]

statement ok
PRAGMA explain_output = OPTIMIZED_ONLY;

statement ok
CREATE TABLE integers AS SELECT * FROM (VALUES (1), (2), (3)) tbl(i);

# "i" does not contain null values, so the coalesce expression is short-circuited
# "17" is never output
query II
EXPLAIN SELECT * FROM integers WHERE (COALESCE(i, 17)=17);
----
logical_opt	<REGEX>:.*EMPTY_RESULT.*

# adding NULLs randomly into the coalesce does not change anything
query II
EXPLAIN SELECT * FROM integers WHERE (COALESCE(NULL, NULL, NULL, i, NULL, 17)=17);
----
logical_opt	<REGEX>:.*EMPTY_RESULT.*

# same here, i is never output, the expression is a constant false
query II
EXPLAIN SELECT * FROM integers WHERE (COALESCE(4, i, 17)=3);
----
logical_opt	<REGEX>:.*EMPTY_RESULT.*

query II
EXPLAIN SELECT * FROM integers WHERE (COALESCE(i, 4, 17)=3);
----
logical_opt	<!REGEX>:.*EMPTY_RESULT.*

# execute the queries
query I
SELECT * FROM integers WHERE (COALESCE(i, 17)=17);
----

query I
SELECT * FROM integers WHERE (COALESCE(NULL, NULL, NULL, i, NULL, 17)=17);
----

query I
SELECT * FROM integers WHERE (COALESCE(4, i, 17)=3);
----

query I
SELECT * FROM integers WHERE (COALESCE(i, 4, 17)=3);
----
3

statement ok
INSERT INTO integers VALUES (NULL);

# after inserting a NULL, the coalesce result changes
query II
EXPLAIN SELECT * FROM integers WHERE (COALESCE(i, 17)=17);
----
logical_opt	<!REGEX>:.*EMPTY_RESULT.*

query II
EXPLAIN SELECT * FROM integers WHERE (COALESCE(NULL, NULL, NULL, i, NULL, 17)=17);
----
logical_opt	<!REGEX>:.*EMPTY_RESULT.*

query II
EXPLAIN SELECT * FROM integers WHERE (COALESCE(4, i, 17)=3);
----
logical_opt	<REGEX>:.*EMPTY_RESULT.*

query II
EXPLAIN SELECT * FROM integers WHERE (COALESCE(i, 4, 17)=3);
----
logical_opt	<!REGEX>:.*EMPTY_RESULT.*

# execute the queries
query I
SELECT * FROM integers WHERE (COALESCE(i, 17)=17);
----
NULL

query I
SELECT * FROM integers WHERE (COALESCE(NULL, NULL, NULL, i, NULL, 17)=17);
----
NULL

query I
SELECT * FROM integers WHERE (COALESCE(4, i, 17)=3);
----

query I
SELECT * FROM integers WHERE (COALESCE(i, 4, 17)=3);
----
3

# Verification compares results, which are different for random().

statement ok
PRAGMA disable_verification

statement ok
PRAGMA disable_verify_fetch_row;

# COALESCE without statistics.

statement ok
SELECT COALESCE (CASE WHEN RANDOM() < 100 THEN RANDOM() ELSE NULL END, NULL, 42)
FROM range(10)