From e5a5502b168494fc5e24f44249bbe095d27c6571 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?mehmet=20furkan=20=C5=9Fahin?= <sahinffurkan@gmail.com>
Date: Thu, 12 Apr 2018 12:58:30 +0300
Subject: [PATCH] Adds support for multiple ANDs in Having

This PR adds support for multiple AND expressions in Having
for pushdown planner. We simply make a call to make_ands_explicit
from MultiLogicalPlanOptimize for the having qual in
workerExtendedOpNode.
---
 .../planner/multi_logical_optimizer.c         | 13 ++++++
 .../expected/multi_having_pushdown.out        | 45 +++++++++++++++++++
 .../regress/sql/multi_having_pushdown.sql     | 23 ++++++++++
 3 files changed, 81 insertions(+)

diff --git a/src/backend/distributed/planner/multi_logical_optimizer.c b/src/backend/distributed/planner/multi_logical_optimizer.c
index a040eafa6..e8973ca78 100644
--- a/src/backend/distributed/planner/multi_logical_optimizer.c
+++ b/src/backend/distributed/planner/multi_logical_optimizer.c
@@ -2133,6 +2133,19 @@ WorkerExtendedOpNode(MultiExtendedOp *originalOpNode,
 		(groupedByDisjointPartitionColumn || pushDownWindowFunction))
 	{
 		workerExtendedOpNode->havingQual = originalOpNode->havingQual;
+
+		/*
+		 * We converted the having expression to a list in subquery pushdown
+		 * planner. However, this query cannot be parsed as it is in the worker.
+		 * We should convert this back to being explicit for worker query
+		 * so that it can be parsed when it hits to the standard planner in
+		 * worker.
+		 */
+		if (IsA(workerExtendedOpNode->havingQual, List))
+		{
+			workerExtendedOpNode->havingQual =
+				(Node *) make_ands_explicit((List *) workerExtendedOpNode->havingQual);
+		}
 	}
 
 	return workerExtendedOpNode;
diff --git a/src/test/regress/expected/multi_having_pushdown.out b/src/test/regress/expected/multi_having_pushdown.out
index 1cd5839ce..cb19b6540 100644
--- a/src/test/regress/expected/multi_having_pushdown.out
+++ b/src/test/regress/expected/multi_having_pushdown.out
@@ -183,3 +183,48 @@ EXPLAIN (COSTS FALSE)
 
 DROP TABLE lineitem_hash;
 DROP TABLE orders_hash;
+SELECT max(value_1) 
+FROM users_table 
+GROUP BY user_id 
+HAVING max(value_2) > 4 AND min(value_2) < 1
+ORDER BY 1;
+ max 
+-----
+   4
+   5
+   5
+(3 rows)
+
+SELECT max(value_1) 
+FROM users_table 
+GROUP BY user_id 
+HAVING max(value_2) > 4 AND min(value_2) < 1 OR count(*) > 10
+ORDER BY 1;
+ max 
+-----
+   4
+   5
+   5
+   5
+(4 rows)
+
+SELECT max(value_1) 
+FROM users_table 
+GROUP BY user_id 
+HAVING max(value_2) > 4 AND min(value_2) < 1 AND count(*) > 20
+ORDER BY 1;
+ max 
+-----
+   5
+   5
+(2 rows)
+
+SELECT max(value_1) 
+FROM users_table 
+GROUP BY user_id 
+HAVING max(value_2) > 0 AND count(*) FILTER (WHERE value_3=2) > 3 AND min(value_2) IN (0,1,2,3);
+ max 
+-----
+   5
+(1 row)
+
diff --git a/src/test/regress/sql/multi_having_pushdown.sql b/src/test/regress/sql/multi_having_pushdown.sql
index 0abfcf1d8..7394c357b 100644
--- a/src/test/regress/sql/multi_having_pushdown.sql
+++ b/src/test/regress/sql/multi_having_pushdown.sql
@@ -55,3 +55,26 @@ EXPLAIN (COSTS FALSE)
 
 DROP TABLE lineitem_hash;
 DROP TABLE orders_hash;
+
+SELECT max(value_1) 
+FROM users_table 
+GROUP BY user_id 
+HAVING max(value_2) > 4 AND min(value_2) < 1
+ORDER BY 1;
+
+SELECT max(value_1) 
+FROM users_table 
+GROUP BY user_id 
+HAVING max(value_2) > 4 AND min(value_2) < 1 OR count(*) > 10
+ORDER BY 1;
+
+SELECT max(value_1) 
+FROM users_table 
+GROUP BY user_id 
+HAVING max(value_2) > 4 AND min(value_2) < 1 AND count(*) > 20
+ORDER BY 1;
+
+SELECT max(value_1) 
+FROM users_table 
+GROUP BY user_id 
+HAVING max(value_2) > 0 AND count(*) FILTER (WHERE value_3=2) > 3 AND min(value_2) IN (0,1,2,3);
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