--
-- CUSTOM_AGGREGATE_SUPPORT
--
-- Create HLL extension if present, print false result otherwise
SELECT CASE WHEN COUNT(*) > 0 THEN
  'CREATE EXTENSION HLL'
ELSE 'SELECT false AS hll_present' END
AS create_cmd FROM pg_available_extensions()
WHERE name = 'hll'
\gset
:create_cmd;
ERROR:  extension "hll" already exists
SET citus.shard_count TO 4;
set citus.coordinator_aggregation_strategy to 'disabled';
CREATE TABLE raw_table (day date, user_id int);
CREATE TABLE daily_uniques(day date, unique_users hll);
SELECT create_distributed_table('raw_table', 'user_id');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

SELECT create_distributed_table('daily_uniques', 'day');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO raw_table
  SELECT day, user_id % 19
  FROM generate_series('2018-05-24'::timestamp, '2018-06-24'::timestamp, '1 day'::interval) as f(day),
       generate_series(1,100) as g(user_id);
INSERT INTO raw_table
  SELECT day, user_id % 13
  FROM generate_series('2018-06-10'::timestamp, '2018-07-10'::timestamp, '1 day'::interval) as f(day),
       generate_series(1,100) as g(user_id);
-- Run hll on raw data
SELECT hll_cardinality(hll_union_agg(agg))
FROM (
  SELECT hll_add_agg(hll_hash_integer(user_id)) AS agg
  FROM raw_table)a;
 hll_cardinality
---------------------------------------------------------------------
              19
(1 row)

-- Aggregate the data into daily_uniques
INSERT INTO daily_uniques
  SELECT day, hll_add_agg(hll_hash_integer(user_id))
  FROM raw_table
  GROUP BY 1;
-- Basic hll_cardinality check on aggregated data
SELECT day, hll_cardinality(unique_users)
FROM daily_uniques
WHERE day >= '2018-06-20' and day <= '2018-06-30'
ORDER BY 2 DESC,1
LIMIT 10;
    day     | hll_cardinality
---------------------------------------------------------------------
 06-20-2018 |              19
 06-21-2018 |              19
 06-22-2018 |              19
 06-23-2018 |              19
 06-24-2018 |              19
 06-25-2018 |              13
 06-26-2018 |              13
 06-27-2018 |              13
 06-28-2018 |              13
 06-29-2018 |              13
(10 rows)

-- Union aggregated data for one week
SELECT hll_cardinality(hll_union_agg(unique_users))
FROM daily_uniques
WHERE day >= '2018-05-24'::date AND day <= '2018-05-31'::date;
 hll_cardinality
---------------------------------------------------------------------
              19
(1 row)

SELECT EXTRACT(MONTH FROM day) AS month, hll_cardinality(hll_union_agg(unique_users))
FROM daily_uniques
WHERE day >= '2018-06-23' AND day <= '2018-07-01'
GROUP BY 1
ORDER BY 1;
 month | hll_cardinality
---------------------------------------------------------------------
     6 |              19
     7 |              13
(2 rows)

-- These are going to be supported after window function support
SELECT day, hll_cardinality(hll_union_agg(unique_users) OVER seven_days)
FROM daily_uniques
WINDOW seven_days AS (ORDER BY day ASC ROWS 6 PRECEDING);
ERROR:  could not run distributed query because the window function that is used cannot be pushed down
HINT:  Window functions are supported in two ways. Either add an equality filter on the distributed tables' partition column or use the window functions with a PARTITION BY clause containing the distribution column
SELECT day, (hll_cardinality(hll_union_agg(unique_users) OVER two_days)) - hll_cardinality(unique_users) AS lost_uniques
FROM daily_uniques
WINDOW two_days AS (ORDER BY day ASC ROWS 1 PRECEDING);
ERROR:  could not run distributed query because the window function that is used cannot be pushed down
HINT:  Window functions are supported in two ways. Either add an equality filter on the distributed tables' partition column or use the window functions with a PARTITION BY clause containing the distribution column
-- Test disabling hash_agg on coordinator query
SET citus.explain_all_tasks to true;
SET hll.force_groupagg to OFF;
EXPLAIN(COSTS OFF)
SELECT
  day, hll_union_agg(unique_users)
FROM
  daily_uniques
GROUP BY(1);
                               QUERY PLAN
---------------------------------------------------------------------
 HashAggregate
   Group Key: remote_scan.day
   ->  Custom Scan (Citus Adaptive)
         Task Count: 4
         Tasks Shown: All
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
(25 rows)

SET hll.force_groupagg to ON;
EXPLAIN(COSTS OFF)
SELECT
  day, hll_union_agg(unique_users)
FROM
  daily_uniques
GROUP BY(1);
                                  QUERY PLAN
---------------------------------------------------------------------
 GroupAggregate
   Group Key: remote_scan.day
   ->  Sort
         Sort Key: remote_scan.day
         ->  Custom Scan (Citus Adaptive)
               Task Count: 4
               Tasks Shown: All
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
(27 rows)

-- Test disabling hash_agg with operator on coordinator query
SET hll.force_groupagg to OFF;
EXPLAIN(COSTS OFF)
SELECT
  day, hll_union_agg(unique_users) || hll_union_agg(unique_users)
FROM
  daily_uniques
GROUP BY(1);
                               QUERY PLAN
---------------------------------------------------------------------
 HashAggregate
   Group Key: remote_scan.day
   ->  Custom Scan (Citus Adaptive)
         Task Count: 4
         Tasks Shown: All
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
(25 rows)

SET hll.force_groupagg to ON;
EXPLAIN(COSTS OFF)
SELECT
  day, hll_union_agg(unique_users) || hll_union_agg(unique_users)
FROM
  daily_uniques
GROUP BY(1);
                                  QUERY PLAN
---------------------------------------------------------------------
 GroupAggregate
   Group Key: remote_scan.day
   ->  Sort
         Sort Key: remote_scan.day
         ->  Custom Scan (Citus Adaptive)
               Task Count: 4
               Tasks Shown: All
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
(27 rows)

-- Test disabling hash_agg with expression on coordinator query
SET hll.force_groupagg to OFF;
EXPLAIN(COSTS OFF)
SELECT
  day, hll_cardinality(hll_union_agg(unique_users))
FROM
  daily_uniques
GROUP BY(1);
                               QUERY PLAN
---------------------------------------------------------------------
 HashAggregate
   Group Key: remote_scan.day
   ->  Custom Scan (Citus Adaptive)
         Task Count: 4
         Tasks Shown: All
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
(25 rows)

SET hll.force_groupagg to ON;
EXPLAIN(COSTS OFF)
SELECT
  day, hll_cardinality(hll_union_agg(unique_users))
FROM
  daily_uniques
GROUP BY(1);
                                  QUERY PLAN
---------------------------------------------------------------------
 GroupAggregate
   Group Key: remote_scan.day
   ->  Sort
         Sort Key: remote_scan.day
         ->  Custom Scan (Citus Adaptive)
               Task Count: 4
               Tasks Shown: All
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  HashAggregate
                           Group Key: day
                           ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
(27 rows)

-- Test disabling hash_agg with having
SET hll.force_groupagg to OFF;
EXPLAIN(COSTS OFF)
SELECT
  day, hll_cardinality(hll_union_agg(unique_users))
FROM
  daily_uniques
GROUP BY(1);
                               QUERY PLAN
---------------------------------------------------------------------
 HashAggregate
   Group Key: remote_scan.day
   ->  Custom Scan (Citus Adaptive)
         Task Count: 4
         Tasks Shown: All
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
         ->  Task
               Node: host=localhost port=xxxxx dbname=regression
               ->  HashAggregate
                     Group Key: day
                     ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
(25 rows)

SET hll.force_groupagg to ON;
EXPLAIN(COSTS OFF)
SELECT
  day, hll_cardinality(hll_union_agg(unique_users))
FROM
  daily_uniques
GROUP BY(1)
HAVING hll_cardinality(hll_union_agg(unique_users)) > 1;
                                                QUERY PLAN
---------------------------------------------------------------------
 GroupAggregate
   Group Key: remote_scan.day
   Filter: (hll_cardinality(hll_union_agg(remote_scan.worker_column_3)) > '1'::double precision)
   ->  Sort
         Sort Key: remote_scan.day
         ->  Custom Scan (Citus Adaptive)
               Task Count: 4
               Tasks Shown: All
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  GroupAggregate
                           Group Key: day
                           Filter: (hll_cardinality(hll_union_agg(unique_users)) > '1'::double precision)
                           ->  Sort
                                 Sort Key: day
                                 ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  GroupAggregate
                           Group Key: day
                           Filter: (hll_cardinality(hll_union_agg(unique_users)) > '1'::double precision)
                           ->  Sort
                                 Sort Key: day
                                 ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  GroupAggregate
                           Group Key: day
                           Filter: (hll_cardinality(hll_union_agg(unique_users)) > '1'::double precision)
                           ->  Sort
                                 Sort Key: day
                                 ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
               ->  Task
                     Node: host=localhost port=xxxxx dbname=regression
                     ->  GroupAggregate
                           Group Key: day
                           Filter: (hll_cardinality(hll_union_agg(unique_users)) > '1'::double precision)
                           ->  Sort
                                 Sort Key: day
                                 ->  Seq Scan on daily_uniques_xxxxxxx daily_uniques
(40 rows)

DROP TABLE raw_table;
DROP TABLE daily_uniques;
-- Check if TopN aggregates work as expected
-- Create TopN extension if present, print false result otherwise
SELECT CASE WHEN COUNT(*) > 0 THEN
  'CREATE EXTENSION TOPN'
ELSE 'SELECT false AS topn_present' END
AS create_topn FROM pg_available_extensions()
WHERE name = 'topn'
\gset
:create_topn;
CREATE TABLE customer_reviews (day date, user_id int, review int);
CREATE TABLE popular_reviewer(day date, reviewers jsonb);
SELECT create_distributed_table('customer_reviews', 'user_id');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

SELECT create_distributed_table('popular_reviewer', 'day');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO customer_reviews
  SELECT day, user_id % 7, review % 5
  FROM generate_series('2018-05-24'::timestamp, '2018-06-24'::timestamp, '1 day'::interval) as f(day),
       generate_series(1,30) as g(user_id), generate_series(0,30) AS r(review);
INSERT INTO customer_reviews
  SELECT day, user_id % 13, review % 3
  FROM generate_series('2018-06-10'::timestamp, '2018-07-10'::timestamp, '1 day'::interval) as f(day),
       generate_series(1,30) as g(user_id), generate_series(0,30) AS r(review);
-- Run topn on raw data
SELECT (topn(agg, 10)).*
FROM (
  SELECT topn_add_agg(user_id::text) AS agg
  FROM customer_reviews
  )a
ORDER BY 2 DESC, 1;
 item | frequency
---------------------------------------------------------------------
 1    |      7843
 2    |      7843
 3    |      6851
 4    |      6851
 0    |      5890
 5    |      5890
 6    |      5890
 7    |      1922
 8    |      1922
 9    |      1922
(10 rows)

-- Aggregate the data into popular_reviewer
INSERT INTO popular_reviewer
  SELECT day, topn_add_agg(user_id::text)
  FROM customer_reviews
  GROUP BY 1;
-- Basic topn check on aggregated data
SELECT day, (topn(reviewers, 10)).*
FROM popular_reviewer
WHERE day >= '2018-06-20' and day <= '2018-06-30'
ORDER BY 3 DESC, 1, 2
LIMIT 10;
    day     | item | frequency
---------------------------------------------------------------------
 06-20-2018 | 1    |       248
 06-20-2018 | 2    |       248
 06-21-2018 | 1    |       248
 06-21-2018 | 2    |       248
 06-22-2018 | 1    |       248
 06-22-2018 | 2    |       248
 06-23-2018 | 1    |       248
 06-23-2018 | 2    |       248
 06-24-2018 | 1    |       248
 06-24-2018 | 2    |       248
(10 rows)

-- Union aggregated data for one week
SELECT (topn(agg, 10)).*
FROM (
	SELECT topn_union_agg(reviewers) AS agg
	FROM popular_reviewer
	WHERE day >= '2018-05-24'::date AND day <= '2018-05-31'::date
	)a
ORDER BY 2 DESC, 1;
 item | frequency
---------------------------------------------------------------------
 1    |      1240
 2    |      1240
 0    |       992
 3    |       992
 4    |       992
 5    |       992
 6    |       992
(7 rows)

SELECT month, (topn(agg, 5)).*
FROM (
	SELECT EXTRACT(MONTH FROM day) AS month, topn_union_agg(reviewers) AS agg
	FROM popular_reviewer
	WHERE day >= '2018-06-23' AND day <= '2018-07-01'
	GROUP BY 1
	ORDER BY 1
	)a
ORDER BY 1, 3 DESC, 2;
 month | item | frequency
---------------------------------------------------------------------
     6 | 1    |      1054
     6 | 2    |      1054
     6 | 3    |       992
     6 | 4    |       992
     6 | 0    |       744
     7 | 1    |        93
     7 | 2    |        93
     7 | 3    |        93
     7 | 4    |        93
     7 | 8    |        62
(10 rows)

-- TODO the following queries will be supported after we fix #2265
-- They work for PG9.6 but not for PG10
SELECT (topn(topn_union_agg(reviewers), 10)).*
FROM popular_reviewer
WHERE day >= '2018-05-24'::date AND day <= '2018-05-31'::date
ORDER BY 2 DESC, 1;
 item | frequency
---------------------------------------------------------------------
 1    |      1240
 2    |      1240
 0    |       992
 3    |       992
 4    |       992
 5    |       992
 6    |       992
(7 rows)

SELECT (topn(topn_add_agg(user_id::text), 10)).*
FROM customer_reviews
ORDER BY 2 DESC, 1;
 item | frequency
---------------------------------------------------------------------
 1    |      7843
 2    |      7843
 3    |      6851
 4    |      6851
 0    |      5890
 5    |      5890
 6    |      5890
 7    |      1922
 8    |      1922
 9    |      1922
(10 rows)

-- The following is going to be supported after window function support
SELECT day, (topn(agg, 10)).*
FROM (
	SELECT day, topn_union_agg(reviewers) OVER seven_days AS agg
	FROM popular_reviewer
	WINDOW seven_days AS (ORDER BY day ASC ROWS 6 PRECEDING)
	)a
ORDER BY 3 DESC, 1, 2
LIMIT 10;
ERROR:  could not run distributed query because the window function that is used cannot be pushed down
HINT:  Window functions are supported in two ways. Either add an equality filter on the distributed tables' partition column or use the window functions with a PARTITION BY clause containing the distribution column
SELECT day, (topn(topn_add_agg(user_id::text) OVER seven_days, 10)).*
FROM customer_reviews
WINDOW seven_days AS (ORDER BY day ASC ROWS 6 PRECEDING)
ORDER BY 3 DESC, 1, 2
LIMIT 10;
ERROR:  could not run distributed query because the window function that is used cannot be pushed down
HINT:  Window functions are supported in two ways. Either add an equality filter on the distributed tables' partition column or use the window functions with a PARTITION BY clause containing the distribution column
DROP TABLE customer_reviews;
DROP TABLE popular_reviewer;
