# Copyright Materialize, Inc. and contributors. All rights reserved.
#
# Use of this software is governed by the Business Source License
# included in the LICENSE file at the root of this repository.
#
# As of the Change Date specified in that file, in accordance with
# the Business Source License, use of this software will be governed
# by the Apache License, Version 2.0.

# This file contains tests for the TopK elision transform
# and interaction of transforms with the TopK operator.

simple conn=mz_system,user=mz_system
ALTER SYSTEM SET unsafe_enable_table_keys = true
----
COMPLETE 0

statement ok
CREATE TABLE test1(a int, b int, c int, d int)

# check that the extra project caused by the CSE is lifted
# through the TopK
query T multiline
EXPLAIN OPTIMIZED PLAN WITH(humanized expressions, arity, join implementations) AS VERBOSE TEXT FOR
SELECT avg(d), sumc, sumd FROM (
SELECT a + b + c as sumc, a + b + d as sumd, d
FROM test1
ORDER BY d NULLS FIRST LIMIT 4
)
GROUP BY sumc, sumd
----
Explained Query:
  Project (#4, #0, #1) // { arity: 3 }
    Map ((bigint_to_numeric(#2{sum_d}) / bigint_to_numeric(case when (#3{count_d} = 0) then null else #3{count_d} end))) // { arity: 5 }
      Reduce group_by=[#1, #2] aggregates=[sum(#0{d}), count(#0{d})] // { arity: 4 }
        TopK order_by=[#0{d} asc nulls_first] limit=4 // { arity: 3 }
          Project (#3{d}, #5, #6) // { arity: 3 }
            Map ((#0{a} + #1{b}), (#4 + #2{c}), (#4 + #3{d})) // { arity: 7 }
              ReadStorage materialize.public.test1 // { arity: 4 }

Source materialize.public.test1

Target cluster: quickstart

EOF

# check that TopK elision is recursive
statement ok
CREATE VIEW plan_test1 AS
SELECT avg(d), sumc, sumd FROM (
SELECT a + b + c as sumc, a + b + d as sumd, d
FROM test1
ORDER BY d
)
GROUP BY sumc, sumd
ORDER BY sumc

query T multiline
EXPLAIN OPTIMIZED PLAN WITH(humanized expressions, arity, join implementations) AS VERBOSE TEXT FOR SELECT * FROM plan_test1
----
Explained Query:
  Project (#4, #0, #1) // { arity: 3 }
    Map ((bigint_to_numeric(#2{sum_d}) / bigint_to_numeric(case when (#3{count_d} = 0) then null else #3{count_d} end))) // { arity: 5 }
      Reduce group_by=[((#0{a} + #1{b}) + #2{c}), ((#0{a} + #1{b}) + #3{d})] aggregates=[sum(#3{d}), count(#3{d})] // { arity: 4 }
        ReadStorage materialize.public.test1 // { arity: 4 }

Source materialize.public.test1

Target cluster: quickstart

EOF

# Test that chained unions get planned with a single union operator.
query T multiline
EXPLAIN OPTIMIZED PLAN WITH(humanized expressions, arity, join implementations) AS VERBOSE TEXT FOR SELECT * FROM test1 UNION ALL SELECT * FROM test1 UNION ALL SELECT * FROM test1
----
Explained Query:
  Union // { arity: 4 }
    ReadStorage materialize.public.test1 // { arity: 4 }
    ReadStorage materialize.public.test1 // { arity: 4 }
    ReadStorage materialize.public.test1 // { arity: 4 }

Source materialize.public.test1

Target cluster: quickstart

EOF

# Test that `limit 0` results in an empty constant with () as the keys

statement ok
CREATE TABLE with_primary_key(a int primary key, b int)

query T multiline
EXPLAIN OPTIMIZED PLAN WITH(TYPES) AS VERBOSE TEXT FOR
select * from (select * from with_primary_key limit 0);
----
Explained Query (fast path):
  Constant <empty>

Target cluster: quickstart

EOF

# Check that TopK fusion transform is wired up

statement ok
create table t1(f1 int, f2 int);

statement ok
create materialized view mv1 as select * from (select * from t1 order by f1 limit 10 offset 2) order by f1 limit 3 offset 1;
----

query T multiline
EXPLAIN OPTIMIZED PLAN WITH(humanized expressions, arity, join implementations) AS VERBOSE TEXT FOR materialized view mv1;
----
materialize.public.mv1:
  TopK order_by=[#0{f1} asc nulls_last] limit=3 offset=3 // { arity: 2 }
    ReadStorage materialize.public.t1 // { arity: 2 }

Source materialize.public.t1

Target cluster: quickstart

EOF