Normalizes Memory Usage, Buckets, Batches for PG15 explain diffs

We create a new function in multi_test_helpers, which is similar
to explain_merge function in PG15. This explain helper function
normalies Memory Usage, Buckets and Batches, and we use it in the
tests which give a different output for PG15.

src/test/regress/expected/multi_explain.out

@@ -301,12 +301,14 @@ Sort
                           Group Key: l_quantity
                           ->  Seq Scan on lineitem_360000 lineitem
 -- Test analyze (with TIMING FALSE and SUMMARY FALSE for consistent output)
+SELECT public.plan_normalize_memory($Q$
 EXPLAIN (COSTS FALSE, ANALYZE TRUE, TIMING FALSE, SUMMARY FALSE)
 	SELECT l_quantity, count(*) count_quantity FROM lineitem
 	GROUP BY l_quantity ORDER BY count_quantity, l_quantity;
+$Q$);
 Sort (actual rows=50 loops=1)
   Sort Key: (COALESCE((pg_catalog.sum(remote_scan.count_quantity))::bigint, '0'::bigint)), remote_scan.l_quantity
-  Sort Method: quicksort  Memory: 27kB
+  Sort Method: quicksort  Memory: xxx
   ->  HashAggregate (actual rows=50 loops=1)
         Group Key: remote_scan.l_quantity
         ->  Custom Scan (Citus Adaptive) (actual rows=100 loops=1)
@@ -369,13 +371,15 @@ Custom Scan (Citus Adaptive) (actual rows=1 loops=1)
 END;
 DROP TABLE t1, t2;
 -- Test query text output, with ANALYZE ON
+SELECT public.plan_normalize_memory($Q$
 EXPLAIN (COSTS FALSE, ANALYZE TRUE, TIMING FALSE, SUMMARY FALSE, VERBOSE TRUE)
 	SELECT l_quantity, count(*) count_quantity FROM lineitem
 	GROUP BY l_quantity ORDER BY count_quantity, l_quantity;
+$Q$);
 Sort (actual rows=50 loops=1)
   Output: remote_scan.l_quantity, (COALESCE((pg_catalog.sum(remote_scan.count_quantity))::bigint, '0'::bigint))
   Sort Key: (COALESCE((pg_catalog.sum(remote_scan.count_quantity))::bigint, '0'::bigint)), remote_scan.l_quantity
-  Sort Method: quicksort  Memory: 27kB
+  Sort Method: quicksort  Memory: xxx
   ->  HashAggregate (actual rows=50 loops=1)
         Output: remote_scan.l_quantity, COALESCE((pg_catalog.sum(remote_scan.count_quantity))::bigint, '0'::bigint)
         Group Key: remote_scan.l_quantity
@@ -1046,12 +1050,14 @@ Custom Scan (Citus Adaptive)
         ->  Delete on lineitem_hash_part_360044 lineitem_hash_part
               ->  Seq Scan on lineitem_hash_part_360044 lineitem_hash_part
 -- Test analyze (with TIMING FALSE and SUMMARY FALSE for consistent output)
+SELECT public.plan_normalize_memory($Q$
 EXPLAIN (COSTS FALSE, ANALYZE TRUE, TIMING FALSE, SUMMARY FALSE)
 	SELECT l_quantity, count(*) count_quantity FROM lineitem
 	GROUP BY l_quantity ORDER BY count_quantity, l_quantity;
+$Q$);
 Sort (actual rows=50 loops=1)
   Sort Key: (COALESCE((pg_catalog.sum(remote_scan.count_quantity))::bigint, '0'::bigint)), remote_scan.l_quantity
-  Sort Method: quicksort  Memory: 27kB
+  Sort Method: quicksort  Memory: xxx
   ->  HashAggregate (actual rows=50 loops=1)
         Group Key: remote_scan.l_quantity
         ->  Custom Scan (Citus Adaptive) (actual rows=100 loops=1)

src/test/regress/expected/multi_test_helpers.out

@@ -72,6 +72,15 @@ BEGIN
   END LOOP;
   RETURN;
 END; $$ language plpgsql;
+-- Create a function to normalize Memory Usage, Buckets, Batches
+CREATE OR REPLACE FUNCTION plan_normalize_memory(explain_command text, out query_plan text)
+RETURNS SETOF TEXT AS $$
+BEGIN
+  FOR query_plan IN execute explain_command LOOP
+    query_plan := regexp_replace(query_plan, '(Memory( Usage)?|Buckets|Batches): \S*',  '\1: xxx', 'g');
+    RETURN NEXT;
+  END LOOP;
+END; $$ language plpgsql;
 -- helper function that returns true if output of given explain has "is not null" (case in-sensitive)
 CREATE OR REPLACE FUNCTION explain_has_is_not_null(explain_command text)
 RETURNS BOOLEAN AS $$

src/test/regress/sql/multi_explain.sql

@@ -122,9 +122,11 @@ EXPLAIN (COSTS FALSE, FORMAT TEXT)
 	GROUP BY l_quantity ORDER BY count_quantity, l_quantity;
 
 -- Test analyze (with TIMING FALSE and SUMMARY FALSE for consistent output)
+SELECT public.plan_normalize_memory($Q$
 EXPLAIN (COSTS FALSE, ANALYZE TRUE, TIMING FALSE, SUMMARY FALSE)
 	SELECT l_quantity, count(*) count_quantity FROM lineitem
 	GROUP BY l_quantity ORDER BY count_quantity, l_quantity;
+$Q$);
 
 -- EXPLAIN ANALYZE doesn't show worker tasks for repartition joins yet
 SET citus.shard_count TO 3;
@@ -142,9 +144,11 @@ END;
 DROP TABLE t1, t2;
 
 -- Test query text output, with ANALYZE ON
+SELECT public.plan_normalize_memory($Q$
 EXPLAIN (COSTS FALSE, ANALYZE TRUE, TIMING FALSE, SUMMARY FALSE, VERBOSE TRUE)
 	SELECT l_quantity, count(*) count_quantity FROM lineitem
 	GROUP BY l_quantity ORDER BY count_quantity, l_quantity;
+$Q$);
 
 -- Test query text output, with ANALYZE OFF
 EXPLAIN (COSTS FALSE, ANALYZE FALSE, TIMING FALSE, SUMMARY FALSE, VERBOSE TRUE)
@@ -488,9 +492,11 @@ EXPLAIN (COSTS FALSE)
 	DELETE FROM lineitem_hash_part;
 
 -- Test analyze (with TIMING FALSE and SUMMARY FALSE for consistent output)
+SELECT public.plan_normalize_memory($Q$
 EXPLAIN (COSTS FALSE, ANALYZE TRUE, TIMING FALSE, SUMMARY FALSE)
 	SELECT l_quantity, count(*) count_quantity FROM lineitem
 	GROUP BY l_quantity ORDER BY count_quantity, l_quantity;
+$Q$);
 
 SET citus.explain_all_tasks TO off;
 

src/test/regress/sql/multi_test_helpers.sql

@@ -78,6 +78,16 @@ BEGIN
   RETURN;
 END; $$ language plpgsql;
 
+-- Create a function to normalize Memory Usage, Buckets, Batches
+CREATE OR REPLACE FUNCTION plan_normalize_memory(explain_command text, out query_plan text)
+RETURNS SETOF TEXT AS $$
+BEGIN
+  FOR query_plan IN execute explain_command LOOP
+    query_plan := regexp_replace(query_plan, '(Memory( Usage)?|Buckets|Batches): \S*',  '\1: xxx', 'g');
+    RETURN NEXT;
+  END LOOP;
+END; $$ language plpgsql;
+
 -- helper function that returns true if output of given explain has "is not null" (case in-sensitive)
 CREATE OR REPLACE FUNCTION explain_has_is_not_null(explain_command text)
 RETURNS BOOLEAN AS $$