Add back pruning coverage lost in last commit.

Because we can't rely on the debuggin message anymore, add a bunch of
explain statements that roughly fulfill the same purpose.

src/test/regress/expected/multi_large_table_pruning.out

@@ -9,6 +9,36 @@ SET citus.large_table_shard_count TO 2;
 SET client_min_messages TO DEBUG2;
 SET citus.task_executor_type TO 'task-tracker';
 -- Single range-repartition join to test join-pruning behaviour.
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	orders, customer
+WHERE
+	o_custkey = c_custkey;
+DEBUG:  join prunable for intervals [1,1000] and [1001,2000]
+DEBUG:  join prunable for intervals [1,1000] and [6001,7000]
+DEBUG:  join prunable for intervals [1001,2000] and [1,1000]
+DEBUG:  join prunable for intervals [1001,2000] and [6001,7000]
+DEBUG:  join prunable for intervals [6001,7000] and [1,1000]
+DEBUG:  join prunable for intervals [6001,7000] and [1001,2000]
+DEBUG:  pruning merge fetch taskId 1
+DETAIL:  Creating dependency on merge taskId 5
+DEBUG:  pruning merge fetch taskId 4
+DETAIL:  Creating dependency on merge taskId 8
+DEBUG:  pruning merge fetch taskId 7
+DETAIL:  Creating dependency on merge taskId 11
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Aggregate
+   ->  Custom Scan (Citus Task-Tracker)
+         Task Count: 3
+         Tasks Shown: None, not supported for re-partition queries
+         ->  MapMergeJob
+               Map Task Count: 2
+               Merge Task Count: 3
+(7 rows)
+
 SELECT
 	count(*)
 FROM
@@ -34,6 +64,25 @@ DETAIL:  Creating dependency on merge taskId 11
 
 -- Single range-repartition join with a selection clause on the partitioned
 -- table to test the case when all map tasks are pruned away.
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	orders, customer
+WHERE
+	o_custkey = c_custkey AND
+	o_orderkey < 0;
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Aggregate
+   ->  Custom Scan (Citus Task-Tracker)
+         Task Count: 0
+         Tasks Shown: None, not supported for re-partition queries
+         ->  MapMergeJob
+               Map Task Count: 0
+               Merge Task Count: 0
+(7 rows)
+
 SELECT
 	count(*)
 FROM
@@ -48,6 +97,25 @@ WHERE
 
 -- Single range-repartition join with a selection clause on the base table to
 -- test the case when all sql tasks are pruned away.
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	orders, customer
+WHERE
+	o_custkey = c_custkey AND
+	c_custkey < 0;
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Aggregate
+   ->  Custom Scan (Citus Task-Tracker)
+         Task Count: 0
+         Tasks Shown: None, not supported for re-partition queries
+         ->  MapMergeJob
+               Map Task Count: 2
+               Merge Task Count: 3
+(7 rows)
+
 SELECT
 	count(*)
 FROM
@@ -63,6 +131,55 @@ WHERE
 -- Dual hash-repartition join test case. Note that this query doesn't produce
 -- meaningful results and is only to test hash-partitioning of two large tables
 -- on non-partition columns.
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	lineitem, customer
+WHERE
+	l_partkey = c_nationkey;
+DEBUG:  join prunable for task partitionId 0 and 1
+DEBUG:  join prunable for task partitionId 0 and 2
+DEBUG:  join prunable for task partitionId 0 and 3
+DEBUG:  join prunable for task partitionId 1 and 0
+DEBUG:  join prunable for task partitionId 1 and 2
+DEBUG:  join prunable for task partitionId 1 and 3
+DEBUG:  join prunable for task partitionId 2 and 0
+DEBUG:  join prunable for task partitionId 2 and 1
+DEBUG:  join prunable for task partitionId 2 and 3
+DEBUG:  join prunable for task partitionId 3 and 0
+DEBUG:  join prunable for task partitionId 3 and 1
+DEBUG:  join prunable for task partitionId 3 and 2
+DEBUG:  pruning merge fetch taskId 1
+DETAIL:  Creating dependency on merge taskId 17
+DEBUG:  pruning merge fetch taskId 2
+DETAIL:  Creating dependency on merge taskId 7
+DEBUG:  pruning merge fetch taskId 4
+DETAIL:  Creating dependency on merge taskId 26
+DEBUG:  pruning merge fetch taskId 5
+DETAIL:  Creating dependency on merge taskId 11
+DEBUG:  pruning merge fetch taskId 7
+DETAIL:  Creating dependency on merge taskId 35
+DEBUG:  pruning merge fetch taskId 8
+DETAIL:  Creating dependency on merge taskId 15
+DEBUG:  pruning merge fetch taskId 10
+DETAIL:  Creating dependency on merge taskId 44
+DEBUG:  pruning merge fetch taskId 11
+DETAIL:  Creating dependency on merge taskId 19
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Aggregate
+   ->  Custom Scan (Citus Task-Tracker)
+         Task Count: 4
+         Tasks Shown: None, not supported for re-partition queries
+         ->  MapMergeJob
+               Map Task Count: 8
+               Merge Task Count: 4
+         ->  MapMergeJob
+               Map Task Count: 3
+               Merge Task Count: 4
+(10 rows)
+
 SELECT
 	count(*)
 FROM
@@ -104,6 +221,28 @@ DETAIL:  Creating dependency on merge taskId 19
 
 -- Dual hash-repartition join with a selection clause on one of the tables to
 -- test the case when all map tasks are pruned away.
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	lineitem, customer
+WHERE
+	l_partkey = c_nationkey AND
+	l_orderkey < 0;
+                            QUERY PLAN                             
+-------------------------------------------------------------------
+ Aggregate
+   ->  Custom Scan (Citus Task-Tracker)
+         Task Count: 0
+         Tasks Shown: None, not supported for re-partition queries
+         ->  MapMergeJob
+               Map Task Count: 0
+               Merge Task Count: 0
+         ->  MapMergeJob
+               Map Task Count: 3
+               Merge Task Count: 4
+(10 rows)
+
 SELECT
 	count(*)
 FROM
@@ -117,6 +256,24 @@ WHERE
 (1 row)
 
 -- Test cases with false in the WHERE clause
+EXPLAIN (COSTS OFF)
+SELECT
+	o_orderkey
+FROM
+	orders INNER JOIN customer ON (o_custkey = c_custkey)
+WHERE
+	false;
+                         QUERY PLAN                          
+-------------------------------------------------------------
+ Custom Scan (Citus Task-Tracker)
+   Task Count: 0
+   Tasks Shown: None, not supported for re-partition queries
+   ->  MapMergeJob
+         Map Task Count: 0
+         Merge Task Count: 0
+(6 rows)
+
+-- execute once, to verify that's handled
 SELECT
 	o_orderkey
 FROM
@@ -127,31 +284,46 @@ WHERE
 ------------
 (0 rows)
 
+EXPLAIN (COSTS OFF)
 SELECT
 	o_orderkey
 FROM
 	orders INNER JOIN customer ON (o_custkey = c_custkey)
 WHERE
 	1=0 AND c_custkey < 0;
- o_orderkey 
+                         QUERY PLAN                          
-------------
+-------------------------------------------------------------
-(0 rows)
+ Custom Scan (Citus Task-Tracker)
+   Task Count: 0
+   Tasks Shown: None, not supported for re-partition queries
+   ->  MapMergeJob
+         Map Task Count: 0
+         Merge Task Count: 0
+(6 rows)
 
+EXPLAIN (COSTS OFF)
 SELECT
 	o_orderkey
 FROM
 	orders INNER JOIN customer ON (o_custkey = c_custkey AND false);
- o_orderkey 
+            QUERY PLAN            
-------------
+----------------------------------
-(0 rows)
+ Custom Scan (Citus Task-Tracker)
+   Task Count: 0
+   Tasks Shown: All
+(3 rows)
 
+EXPLAIN (COSTS OFF)
 SELECT
 	o_orderkey
 FROM
 	orders, customer
 WHERE
 	o_custkey = c_custkey AND false;
- o_orderkey 
+            QUERY PLAN            
-------------
+----------------------------------
-(0 rows)
+ Custom Scan (Citus Task-Tracker)
+   Task Count: 0
+   Tasks Shown: All
+(3 rows)
 

src/test/regress/expected/multi_null_minmax_value_pruning.out

@@ -5,6 +5,10 @@
 -- and that we don't partition or join prune shards that have null values.
 ALTER SEQUENCE pg_catalog.pg_dist_shardid_seq RESTART 760000;
 SET client_min_messages TO DEBUG2;
+SET citus.explain_all_tasks TO on;
+-- to avoid differing explain output - executor doesn't matter,
+-- because were testing pruning here.
+SET citus.task_executor_type TO 'real-time';
 -- Change configuration to treat lineitem and orders tables as large
 SET citus.large_table_shard_count TO 2;
 SELECT shardminvalue, shardmaxvalue from pg_dist_shard WHERE shardid = 290000;
@@ -21,23 +25,34 @@ SELECT shardminvalue, shardmaxvalue from pg_dist_shard WHERE shardid = 290001;
 
 -- Check that partition and join pruning works when min/max values exist
 -- Adding l_orderkey = 1 to make the query not router executable
+EXPLAIN (COSTS FALSE)
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030 or l_orderkey = 1;
- l_orderkey | l_linenumber | l_shipdate 
+                              QUERY PLAN                               
-------------+--------------+------------
+-----------------------------------------------------------------------
-          1 |            1 | 03-13-1996
+ Custom Scan (Citus Real-Time)
-          1 |            2 | 04-12-1996
+   Task Count: 2
-          1 |            3 | 01-29-1996
+   Tasks Shown: All
-          1 |            4 | 04-21-1996
+   ->  Task
-          1 |            5 | 03-30-1996
+         Node: host=localhost port=57637 dbname=regression
-          1 |            6 | 01-30-1996
+         ->  Bitmap Heap Scan on lineitem_290000 lineitem
-       9030 |            1 | 09-02-1998
+               Recheck Cond: ((l_orderkey = 9030) OR (l_orderkey = 1))
-       9030 |            2 | 08-19-1998
+               ->  BitmapOr
-       9030 |            3 | 08-27-1998
+                     ->  Bitmap Index Scan on lineitem_pkey_290000
-       9030 |            4 | 07-20-1998
+                           Index Cond: (l_orderkey = 9030)
-       9030 |            5 | 09-29-1998
+                     ->  Bitmap Index Scan on lineitem_pkey_290000
-       9030 |            6 | 09-03-1998
+                           Index Cond: (l_orderkey = 1)
-(12 rows)
+   ->  Task
+         Node: host=localhost port=57638 dbname=regression
+         ->  Bitmap Heap Scan on lineitem_290004 lineitem
+               Recheck Cond: ((l_orderkey = 9030) OR (l_orderkey = 1))
+               ->  BitmapOr
+                     ->  Bitmap Index Scan on lineitem_pkey_290004
+                           Index Cond: (l_orderkey = 9030)
+                     ->  Bitmap Index Scan on lineitem_pkey_290004
+                           Index Cond: (l_orderkey = 1)
+(21 rows)
 
+EXPLAIN (COSTS FALSE)
 SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 	WHERE l_orderkey = o_orderkey;
 DEBUG:  join prunable for intervals [1,1509] and [8997,14946]
@@ -48,25 +63,91 @@ DEBUG:  join prunable for intervals [8997,10560] and [1,5986]
 DEBUG:  join prunable for intervals [10560,12036] and [1,5986]
 DEBUG:  join prunable for intervals [12036,13473] and [1,5986]
 DEBUG:  join prunable for intervals [13473,14947] and [1,5986]
-  sum  |        avg         
+                                              QUERY PLAN                                              
--------+--------------------
+------------------------------------------------------------------------------------------------------
- 36086 | 3.0076679446574429
+ Aggregate
-(1 row)
+   ->  Custom Scan (Citus Real-Time)
+         Task Count: 8
+         Tasks Shown: All
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290001 on lineitem_290001 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (lineitem.l_orderkey = orders.o_orderkey)
+                           ->  Index Only Scan using lineitem_pkey_290000 on lineitem_290000 lineitem
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290003 on lineitem_290003 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290002 on lineitem_290002 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290005 on lineitem_290005 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290004 on lineitem_290004 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290007 on lineitem_290007 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290006 on lineitem_290006 lineitem
+(60 rows)
 
 -- Now set the minimum value for a shard to null. Then check that we don't apply
 -- partition or join pruning for the shard with null min value.
 UPDATE pg_dist_shard SET shardminvalue = NULL WHERE shardid = 290000;
+EXPLAIN (COSTS FALSE)
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030;
- l_orderkey | l_linenumber | l_shipdate 
+                                  QUERY PLAN                                   
-------------+--------------+------------
+-------------------------------------------------------------------------------
-       9030 |            1 | 09-02-1998
+ Custom Scan (Citus Real-Time)
-       9030 |            2 | 08-19-1998
+   Task Count: 2
-       9030 |            3 | 08-27-1998
+   Tasks Shown: All
-       9030 |            4 | 07-20-1998
+   ->  Task
-       9030 |            5 | 09-29-1998
+         Node: host=localhost port=57637 dbname=regression
-       9030 |            6 | 09-03-1998
+         ->  Index Scan using lineitem_pkey_290000 on lineitem_290000 lineitem
-(6 rows)
+               Index Cond: (l_orderkey = 9030)
+   ->  Task
+         Node: host=localhost port=57638 dbname=regression
+         ->  Index Scan using lineitem_pkey_290004 on lineitem_290004 lineitem
+               Index Cond: (l_orderkey = 9030)
+(11 rows)
 
+EXPLAIN (COSTS FALSE)
 SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 	WHERE l_orderkey = o_orderkey;
 DEBUG:  join prunable for intervals [1509,2951] and [8997,14946]
@@ -76,25 +157,102 @@ DEBUG:  join prunable for intervals [8997,10560] and [1,5986]
 DEBUG:  join prunable for intervals [10560,12036] and [1,5986]
 DEBUG:  join prunable for intervals [12036,13473] and [1,5986]
 DEBUG:  join prunable for intervals [13473,14947] and [1,5986]
-  sum  |        avg         
+                                              QUERY PLAN                                              
--------+--------------------
+------------------------------------------------------------------------------------------------------
- 36086 | 3.0076679446574429
+ Aggregate
-(1 row)
+   ->  Custom Scan (Citus Real-Time)
+         Task Count: 9
+         Tasks Shown: All
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290001 on lineitem_290001 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (lineitem.l_orderkey = orders.o_orderkey)
+                           ->  Index Only Scan using lineitem_pkey_290000 on lineitem_290000 lineitem
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290003 on lineitem_290003 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290000 on lineitem_290000 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290005 on lineitem_290005 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290002 on lineitem_290002 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290007 on lineitem_290007 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290004 on lineitem_290004 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290006 on lineitem_290006 lineitem
+(67 rows)
 
 -- Next, set the maximum value for another shard to null. Then check that we
 -- don't apply partition or join pruning for this other shard either.
 UPDATE pg_dist_shard SET shardmaxvalue = NULL WHERE shardid = 290001;
+EXPLAIN (COSTS FALSE)
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030;
- l_orderkey | l_linenumber | l_shipdate 
+                                  QUERY PLAN                                   
-------------+--------------+------------
+-------------------------------------------------------------------------------
-       9030 |            1 | 09-02-1998
+ Custom Scan (Citus Real-Time)
-       9030 |            2 | 08-19-1998
+   Task Count: 3
-       9030 |            3 | 08-27-1998
+   Tasks Shown: All
-       9030 |            4 | 07-20-1998
+   ->  Task
-       9030 |            5 | 09-29-1998
+         Node: host=localhost port=57637 dbname=regression
-       9030 |            6 | 09-03-1998
+         ->  Index Scan using lineitem_pkey_290001 on lineitem_290001 lineitem
-(6 rows)
+               Index Cond: (l_orderkey = 9030)
+   ->  Task
+         Node: host=localhost port=57638 dbname=regression
+         ->  Index Scan using lineitem_pkey_290000 on lineitem_290000 lineitem
+               Index Cond: (l_orderkey = 9030)
+   ->  Task
+         Node: host=localhost port=57637 dbname=regression
+         ->  Index Scan using lineitem_pkey_290004 on lineitem_290004 lineitem
+               Index Cond: (l_orderkey = 9030)
+(15 rows)
 
+EXPLAIN (COSTS FALSE)
 SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 	WHERE l_orderkey = o_orderkey;
 DEBUG:  join prunable for intervals [2951,4455] and [8997,14946]
@@ -103,25 +261,105 @@ DEBUG:  join prunable for intervals [8997,10560] and [1,5986]
 DEBUG:  join prunable for intervals [10560,12036] and [1,5986]
 DEBUG:  join prunable for intervals [12036,13473] and [1,5986]
 DEBUG:  join prunable for intervals [13473,14947] and [1,5986]
-  sum  |        avg         
+                                              QUERY PLAN                                              
--------+--------------------
+------------------------------------------------------------------------------------------------------
- 36086 | 3.0076679446574429
+ Aggregate
-(1 row)
+   ->  Custom Scan (Citus Real-Time)
+         Task Count: 10
+         Tasks Shown: All
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290001 on lineitem_290001 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (lineitem.l_orderkey = orders.o_orderkey)
+                           ->  Index Only Scan using lineitem_pkey_290000 on lineitem_290000 lineitem
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290001 on lineitem_290001 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290000 on lineitem_290000 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290003 on lineitem_290003 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290002 on lineitem_290002 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290005 on lineitem_290005 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290004 on lineitem_290004 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290007 on lineitem_290007 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290006 on lineitem_290006 lineitem
+(74 rows)
 
 -- Last, set the minimum value to 0 and check that we don't treat it as null. We
 -- should apply partition and join pruning for this shard now.
 UPDATE pg_dist_shard SET shardminvalue = '0' WHERE shardid = 290000;
+EXPLAIN (COSTS FALSE)
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030;
- l_orderkey | l_linenumber | l_shipdate 
+                                  QUERY PLAN                                   
-------------+--------------+------------
+-------------------------------------------------------------------------------
-       9030 |            1 | 09-02-1998
+ Custom Scan (Citus Real-Time)
-       9030 |            2 | 08-19-1998
+   Task Count: 2
-       9030 |            3 | 08-27-1998
+   Tasks Shown: All
-       9030 |            4 | 07-20-1998
+   ->  Task
-       9030 |            5 | 09-29-1998
+         Node: host=localhost port=57637 dbname=regression
-       9030 |            6 | 09-03-1998
+         ->  Index Scan using lineitem_pkey_290001 on lineitem_290001 lineitem
-(6 rows)
+               Index Cond: (l_orderkey = 9030)
+   ->  Task
+         Node: host=localhost port=57638 dbname=regression
+         ->  Index Scan using lineitem_pkey_290004 on lineitem_290004 lineitem
+               Index Cond: (l_orderkey = 9030)
+(11 rows)
 
+EXPLAIN (COSTS FALSE)
 SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 	WHERE l_orderkey = o_orderkey;
 DEBUG:  join prunable for intervals [0,1509] and [8997,14946]
@@ -131,10 +369,76 @@ DEBUG:  join prunable for intervals [8997,10560] and [1,5986]
 DEBUG:  join prunable for intervals [10560,12036] and [1,5986]
 DEBUG:  join prunable for intervals [12036,13473] and [1,5986]
 DEBUG:  join prunable for intervals [13473,14947] and [1,5986]
-  sum  |        avg         
+                                              QUERY PLAN                                              
--------+--------------------
+------------------------------------------------------------------------------------------------------
- 36086 | 3.0076679446574429
+ Aggregate
-(1 row)
+   ->  Custom Scan (Citus Real-Time)
+         Task Count: 9
+         Tasks Shown: All
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290001 on lineitem_290001 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (lineitem.l_orderkey = orders.o_orderkey)
+                           ->  Index Only Scan using lineitem_pkey_290000 on lineitem_290000 lineitem
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290001 on lineitem_290001 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290002 on lineitem_290002 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290008 on orders_290008 orders
+                           ->  Index Only Scan using lineitem_pkey_290003 on lineitem_290003 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290004 on lineitem_290004 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290005 on lineitem_290005 lineitem
+         ->  Task
+               Node: host=localhost port=57638 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290006 on lineitem_290006 lineitem
+         ->  Task
+               Node: host=localhost port=57637 dbname=regression
+               ->  Aggregate
+                     ->  Merge Join
+                           Merge Cond: (orders.o_orderkey = lineitem.l_orderkey)
+                           ->  Index Only Scan using orders_pkey_290009 on orders_290009 orders
+                           ->  Index Only Scan using lineitem_pkey_290007 on lineitem_290007 lineitem
+(67 rows)
 
 -- Set minimum and maximum values for two shards back to their original values
 UPDATE pg_dist_shard SET shardminvalue = '1' WHERE shardid = 290000;

src/test/regress/expected/multi_partition_pruning.out

@@ -4,8 +4,6 @@
 -- Tests to verify that we correctly prune unreferenced shards. For this, we
 -- need to increase the logging verbosity of messages displayed on the client.
 ALTER SEQUENCE pg_catalog.pg_dist_shardid_seq RESTART 770000;
-SET citus.explain_distributed_queries TO off;
-SET client_min_messages TO DEBUG2;
 -- Adding additional l_orderkey = 1 to make this query not router executable
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030 or l_orderkey = 1;
  l_orderkey | l_linenumber | l_shipdate 
@@ -146,32 +144,46 @@ INSERT INTO pg_dist_shard_placement (shardid, shardstate, shardlength, nodename,
 	GROUP BY nodename, nodeport
 	ORDER BY nodename, nodeport ASC
 	LIMIT 1;
--- Verify that shard pruning works. Note that these queries should all prune
+-- Verify that shard pruning works. Note that these queries should all
--- one shard.
+-- prune one shard (see task count).  As these tables don't exist
-EXPLAIN SELECT count(*) FROM varchar_partitioned_table WHERE varchar_column = 'BA2';
+-- remotely, temporarily disable WARNING messages.
+SET client_min_messages TO ERROR;
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM varchar_partitioned_table WHERE varchar_column = 'BA2';
                    QUERY PLAN                    
------------------------------------------------------------------------
+-------------------------------------------------
- Aggregate  (cost=0.00..0.00 rows=0 width=0)
+ Aggregate
-   ->  Custom Scan (Citus Real-Time)  (cost=0.00..0.00 rows=0 width=0)
+   ->  Custom Scan (Citus Real-Time)
-         explain statements for distributed queries are not enabled
+         Task Count: 1
-(3 rows)
+         Tasks Shown: All
+         ->  Task
+               Error: Could not get remote plan.
+(6 rows)
 
-EXPLAIN SELECT count(*) FROM array_partitioned_table
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM array_partitioned_table
 	WHERE array_column > '{BA1000U2AMO4ZGX, BZZXSP27F21T6}';
                    QUERY PLAN                    
------------------------------------------------------------------------
+-------------------------------------------------
- Aggregate  (cost=0.00..0.00 rows=0 width=0)
+ Aggregate
-   ->  Custom Scan (Citus Real-Time)  (cost=0.00..0.00 rows=0 width=0)
+   ->  Custom Scan (Citus Real-Time)
-         explain statements for distributed queries are not enabled
+         Task Count: 1
-(3 rows)
+         Tasks Shown: All
+         ->  Task
+               Error: Could not get remote plan.
+(6 rows)
 
-EXPLAIN SELECT count(*) FROM composite_partitioned_table
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM composite_partitioned_table
 	WHERE composite_column < '(b,5,c)'::composite_type;
                    QUERY PLAN                    
------------------------------------------------------------------------
+-------------------------------------------------
- Aggregate  (cost=0.00..0.00 rows=0 width=0)
+ Aggregate
-   ->  Custom Scan (Citus Real-Time)  (cost=0.00..0.00 rows=0 width=0)
+   ->  Custom Scan (Citus Real-Time)
-         explain statements for distributed queries are not enabled
+         Task Count: 1
-(3 rows)
+         Tasks Shown: All
+         ->  Task
+               Error: Could not get remote plan.
+(6 rows)
 
 SET client_min_messages TO NOTICE;

src/test/regress/multi_task_tracker_extra_schedule

@@ -34,7 +34,6 @@ test: multi_average_expression multi_working_columns
 test: multi_array_agg
 test: multi_agg_type_conversion multi_count_type_conversion
 test: multi_hash_pruning
-test: multi_null_minmax_value_pruning
 test: multi_query_directory_cleanup
 test: multi_utility_statements
 test: multi_dropped_column_aliases
@@ -50,7 +49,6 @@ test: multi_tpch_query7 multi_tpch_query7_nested
 # Parallel tests to check our join order planning logic. Note that we load data
 # below; and therefore these tests should come after the execution tests.
 # ----------
-test: multi_join_order_additional
 test: multi_load_more_data
 test: multi_join_order_tpch_large
 

src/test/regress/sql/multi_large_table_pruning.sql

@@ -14,7 +14,13 @@ SET client_min_messages TO DEBUG2;
 SET citus.task_executor_type TO 'task-tracker';
 
 -- Single range-repartition join to test join-pruning behaviour.
-
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	orders, customer
+WHERE
+	o_custkey = c_custkey;
 SELECT
 	count(*)
 FROM
@@ -24,7 +30,14 @@ WHERE
 
 -- Single range-repartition join with a selection clause on the partitioned
 -- table to test the case when all map tasks are pruned away.
-
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	orders, customer
+WHERE
+	o_custkey = c_custkey AND
+	o_orderkey < 0;
 SELECT
 	count(*)
 FROM
@@ -35,7 +48,14 @@ WHERE
 
 -- Single range-repartition join with a selection clause on the base table to
 -- test the case when all sql tasks are pruned away.
-
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	orders, customer
+WHERE
+	o_custkey = c_custkey AND
+	c_custkey < 0;
 SELECT
 	count(*)
 FROM
@@ -47,7 +67,13 @@ WHERE
 -- Dual hash-repartition join test case. Note that this query doesn't produce
 -- meaningful results and is only to test hash-partitioning of two large tables
 -- on non-partition columns.
-
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	lineitem, customer
+WHERE
+	l_partkey = c_nationkey;
 SELECT
 	count(*)
 FROM
@@ -57,7 +83,14 @@ WHERE
 
 -- Dual hash-repartition join with a selection clause on one of the tables to
 -- test the case when all map tasks are pruned away.
-
+EXPLAIN (COSTS OFF)
+SELECT
+	count(*)
+FROM
+	lineitem, customer
+WHERE
+	l_partkey = c_nationkey AND
+	l_orderkey < 0;
 SELECT
 	count(*)
 FROM
@@ -67,6 +100,14 @@ WHERE
 	l_orderkey < 0;
 
 -- Test cases with false in the WHERE clause
+EXPLAIN (COSTS OFF)
+SELECT
+	o_orderkey
+FROM
+	orders INNER JOIN customer ON (o_custkey = c_custkey)
+WHERE
+	false;
+-- execute once, to verify that's handled
 SELECT
 	o_orderkey
 FROM
@@ -74,6 +115,7 @@ FROM
 WHERE
 	false;
 
+EXPLAIN (COSTS OFF)
 SELECT
 	o_orderkey
 FROM
@@ -81,11 +123,13 @@ FROM
 WHERE
 	1=0 AND c_custkey < 0;
 
+EXPLAIN (COSTS OFF)
 SELECT
 	o_orderkey
 FROM
 	orders INNER JOIN customer ON (o_custkey = c_custkey AND false);
 
+EXPLAIN (COSTS OFF)
 SELECT
 	o_orderkey
 FROM

src/test/regress/sql/multi_null_minmax_value_pruning.sql

@@ -8,8 +8,11 @@
 
 ALTER SEQUENCE pg_catalog.pg_dist_shardid_seq RESTART 760000;
 
-
 SET client_min_messages TO DEBUG2;
+SET citus.explain_all_tasks TO on;
+-- to avoid differing explain output - executor doesn't matter,
+-- because were testing pruning here.
+SET citus.task_executor_type TO 'real-time';
 
 -- Change configuration to treat lineitem and orders tables as large
 
@@ -20,8 +23,10 @@ SELECT shardminvalue, shardmaxvalue from pg_dist_shard WHERE shardid = 290001;
 
 -- Check that partition and join pruning works when min/max values exist
 -- Adding l_orderkey = 1 to make the query not router executable
+EXPLAIN (COSTS FALSE)
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030 or l_orderkey = 1;
 
+EXPLAIN (COSTS FALSE)
 SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 	WHERE l_orderkey = o_orderkey;
 
@@ -30,8 +35,10 @@ SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 
 UPDATE pg_dist_shard SET shardminvalue = NULL WHERE shardid = 290000;
 
+EXPLAIN (COSTS FALSE)
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030;
 
+EXPLAIN (COSTS FALSE)
 SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 	WHERE l_orderkey = o_orderkey;
 
@@ -40,8 +47,10 @@ SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 
 UPDATE pg_dist_shard SET shardmaxvalue = NULL WHERE shardid = 290001;
 
+EXPLAIN (COSTS FALSE)
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030;
 
+EXPLAIN (COSTS FALSE)
 SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 	WHERE l_orderkey = o_orderkey;
 
@@ -50,8 +59,10 @@ SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 
 UPDATE pg_dist_shard SET shardminvalue = '0' WHERE shardid = 290000;
 
+EXPLAIN (COSTS FALSE)
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030;
 
+EXPLAIN (COSTS FALSE)
 SELECT sum(l_linenumber), avg(l_linenumber) FROM lineitem, orders
 	WHERE l_orderkey = o_orderkey;
 

src/test/regress/sql/multi_partition_pruning.sql

@@ -8,10 +8,6 @@
 
 ALTER SEQUENCE pg_catalog.pg_dist_shardid_seq RESTART 770000;
 
-
-SET citus.explain_distributed_queries TO off;
-SET client_min_messages TO DEBUG2;
-
 -- Adding additional l_orderkey = 1 to make this query not router executable
 SELECT l_orderkey, l_linenumber, l_shipdate FROM lineitem WHERE l_orderkey = 9030 or l_orderkey = 1;
 
@@ -131,15 +127,21 @@ INSERT INTO pg_dist_shard_placement (shardid, shardstate, shardlength, nodename,
 	ORDER BY nodename, nodeport ASC
 	LIMIT 1;
 
--- Verify that shard pruning works. Note that these queries should all prune
+-- Verify that shard pruning works. Note that these queries should all
--- one shard.
+-- prune one shard (see task count).  As these tables don't exist
+-- remotely, temporarily disable WARNING messages.
+SET client_min_messages TO ERROR;
 
-EXPLAIN SELECT count(*) FROM varchar_partitioned_table WHERE varchar_column = 'BA2';
 
-EXPLAIN SELECT count(*) FROM array_partitioned_table
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM varchar_partitioned_table WHERE varchar_column = 'BA2';
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM array_partitioned_table
 	WHERE array_column > '{BA1000U2AMO4ZGX, BZZXSP27F21T6}';
 
-EXPLAIN SELECT count(*) FROM composite_partitioned_table
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM composite_partitioned_table
 	WHERE composite_column < '(b,5,c)'::composite_type;
 
 SET client_min_messages TO NOTICE;