Cherry pick Rows out in EXPLAIN ANALYZE

src/backend/cdb/cdbvars.c

@@ -278,6 +278,7 @@ int			gp_hashjoin_tuples_per_bucket = 5;
 int			gp_motion_slice_noop = 0;
 
 /* Apache Cloudberry Experimental Feature GUCs */
+bool		gp_enable_explain_rows_out = false;
 bool		gp_enable_explain_allstat = false;
 bool		gp_enable_motion_deadlock_sanity = false;	/* planning time sanity
 														 * check */

src/backend/commands/explain_gp.c

@@ -944,7 +944,7 @@ cdbexplain_collectStatsFromNode(PlanState *planstate, CdbExplain_SendStatCtx *ct
  */
 typedef struct CdbExplain_DepStatAcc
 {
-	/* vmax, vsum, vcnt, segmax */
+	/* vmax, vmin, vsum, vcnt, segmax, segmin */
 	CdbExplain_Agg agg;
 	/* max's received StatHdr */
 	CdbExplain_StatHdr *rshmax;
@@ -1801,6 +1801,56 @@ cdbexplain_showExecStats(struct PlanState *planstate, ExplainState *es)
 	}
 	pfree(extraData.data);
 
+	/*
+	 * Print "Rows out"
+	 */
+
+	if (gp_enable_explain_rows_out && es->analyze && ns->ninst > 0) {
+        double ntuples_max = ns->ntuples.vmax;
+        int ntuples_imax = ns->ntuples.imax;
+		int ntuples_wmax = ns->ntuples.wmax;
+        double ntuples_min = ns->ntuples.vmin;
+        int ntuples_imin = ns->ntuples.imin;
+		int ntuples_wmin = ns->ntuples.wmin;
+        double ntuples_avg = cdbexplain_agg_avg(&ns->ntuples);
+
+		int segments = ns->ninst;
+		int workers = ns->ntuples.vcnt;
+
+        if (es->format == EXPLAIN_FORMAT_TEXT)
+        {
+            /*
+             * create a header for all stats: separate each individual stat by an
+             * underscore, separate the grouped stats for each node by a slash
+             */
+            appendStringInfoSpaces(es->str, es->indent * 2);
+            appendStringInfoString(es->str, "Rows out: ");
+
+            appendStringInfo(es->str,
+                                 "%.2f rows avg x %d workers from %d segments, %.0f rows max (seg%d worker%d), %.0f rows min (seg%d worker%d).\n",
+                                 ntuples_avg,
+                                 workers,
+								 segments,
+                                 ntuples_max,
+                                 ntuples_imax,
+								 ntuples_wmax,
+                                 ntuples_min,
+                                 ntuples_imin,
+								 ntuples_wmin);
+        }
+        else {
+            ExplainPropertyInteger("Workers", NULL,workers, es);
+			ExplainPropertyInteger("Segments", NULL, segments, es);
+            ExplainPropertyFloat("Average Rows", NULL, ntuples_avg, 1, es);
+            ExplainPropertyFloat("Max Rows", NULL, ntuples_max, 0, es);
+            ExplainPropertyInteger("Max Rows Segment", NULL, ntuples_imax, es);
+			ExplainPropertyInteger("Max Rows Worker", NULL, ntuples_wmax, es);
+            ExplainPropertyFloat("Min Rows", NULL, ntuples_min, 0, es);
+            ExplainPropertyInteger("Min Rows Segment", NULL, ntuples_imin, es);
+			ExplainPropertyInteger("Min Rows Segment", NULL, ntuples_wmin, es);
+        }
+    }
+
 	/*
 	 * Dump stats for all workers.
 	 */

src/backend/utils/misc/guc_gp.c

@@ -814,6 +814,17 @@ struct config_bool ConfigureNamesBool_gp[] =
 		NULL, NULL, NULL
 	},
 
+	{
+		{"gp_enable_explain_rows_out", PGC_USERSET, CLIENT_CONN_OTHER,
+			gettext_noop("Print avg, min and max rows out and which segments reach them in EXPLAIN ANALYZE."),
+			NULL,
+			GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
+		},
+		&gp_enable_explain_rows_out,
+		false,
+		NULL, NULL, NULL
+	},
+
 	{
 		{"gp_enable_explain_allstat", PGC_USERSET, CLIENT_CONN_OTHER,
 			gettext_noop("Experimental feature: dump stats for all segments in EXPLAIN ANALYZE."),

src/include/cdb/cdbexplain.h

@@ -26,18 +26,26 @@ struct CdbExplain_ShowStatCtx;          /* private, in "cdb/cdbexplain.c" */
 typedef struct
 {
 	double		vmax;			/* maximum value of statistic */
+    double		vmin;			/* minimum value of statistic */
 	double		vsum;			/* sum of values */
 	int			vcnt;			/* count of values > 0 */
 	int			imax;			/* id of 1st observation having maximum value */
+    int			imin;			/* id of 1st observation having minimum value */
+    int			wmax;			/* worker id of 1st observation having maximum value */
+    int			wmin;			/* worker id of 1st observation having minimum value */
 } CdbExplain_Agg;
 
 static inline void
 cdbexplain_agg_init0(CdbExplain_Agg *agg)
 {
     agg->vmax = 0;
+    agg->vmin = 0;
     agg->vsum = 0;
     agg->vcnt = 0;
     agg->imax = 0;
+    agg->imin = 0;
+    agg->wmax = 0;
+    agg->wmin = 0;
 }
 
 static inline bool
@@ -48,13 +56,23 @@ cdbexplain_agg_upd(CdbExplain_Agg *agg, double v, int id)
         agg->vsum += v;
         agg->vcnt++;
 
+        if (v < agg->vmin ||
+            agg->vcnt == 1)
+        {
+            agg->vmin = v;
+            agg->imin = id;
+            agg->wmin = agg->vcnt - 1;
+        }
+
         if (v > agg->vmax ||
             agg->vcnt == 1)
         {
             agg->vmax = v;
             agg->imax = id;
-            return true;
+            agg->wmax = agg->vcnt - 1;
         }
+
+        return agg->imin == id || agg->imax == id;
     }
     return false;
 }

src/include/cdb/cdbvars.h

@@ -613,6 +613,12 @@ extern bool gp_enable_agg_pushdown;
  */
 extern bool gp_enable_preunique;
 
+/* May Cloudberry print statistics as average, minimum and maximum rows out
+ * and on which segments reach them for each node during EXPLAIN ANALYZE?
+ *
+ */
+extern bool gp_enable_explain_rows_out;
+
 /* May Cloudberry dump statistics for all segments as a huge ugly string
  * during EXPLAIN ANALYZE?
  *

src/include/utils/unsync_guc_name.h

@@ -182,6 +182,7 @@
 		"gp_enable_agg_pushdown",
 		"gp_enable_ao_indexscan",
 		"gp_enable_direct_dispatch",
+		"gp_enable_explain_rows_out",
 		"gp_enable_explain_allstat",
 		"gp_enable_fast_sri",
 		"gp_enable_global_deadlock_detector",

src/test/regress/expected/cbdb_parallel.out

@@ -3068,6 +3068,34 @@ select t1_anti.a, t1_anti.b from t1_anti left join t2_anti on t1_anti.a = t2_ant
  2 |  
 (4 rows)
 
+abort;
+-- test rows out
+-- start_matchsubs
+-- m/\(actual rows=\d+ loops=\d+\)/
+-- s/\(actual rows=\d+ loops=\d+\)/(actual rows=# loops=#)/
+-- m/Rows Removed by Filter: \d+/
+-- s/Rows Removed by Filter: \d+/Rows Removed by Filter: ###/
+-- m/\d+ rows max \(seg\d+ worker\d+\), \d+ rows min \(seg\d+ worker\d+\)/
+-- s/\d+ rows max \(seg\d+ worker\d+\), \d+ rows min \(seg\d+ worker\d+\)/##### rows max (seg# worker#), ##### rows min (seg# worker#)/
+-- end_matchsubs
+begin;
+create table tt (a int, b int) with(parallel_workers=2) distributed by(a, b);
+insert into tt select * from generate_series(1,1000)a,generate_series(1,1000)b;
+set local enable_parallel = on;
+set local max_parallel_workers_per_gather = 2;
+set local gp_enable_explain_rows_out = on;
+explain(costs off, summary off, timing off, analyze) select * from tt where a > b;
+                                                           QUERY PLAN                                                           
+--------------------------------------------------------------------------------------------------------------------------------
+ Gather Motion 6:1  (slice1; segments: 6) (actual rows=499500 loops=1)
+   Rows out: 499500.00 rows avg x 1 workers from 1 segments, 499500 rows max (seg-1 worker0), 499500 rows min (seg-1 worker0).
+   ->  Parallel Seq Scan on tt (actual rows=86074 loops=1)
+         Filter: (a > b)
+         Rows Removed by Filter: 84852
+         Rows out: 83250.00 rows avg x 6 workers from 3 segments, 86144 rows max (seg2 worker4), 80391 rows min (seg1 worker2).
+ Optimizer: Postgres query optimizer
+(7 rows)
+
 abort;
 -- start_ignore
 drop schema test_parallel cascade;

src/test/regress/expected/gp_explain.out

@@ -436,6 +436,42 @@ explain analyze SELECT * FROM explaintest;
 (8 rows)
 
 set gp_enable_explain_allstat=DEFAULT;
+-- Test explain rows out.
+begin;
+set local gp_enable_explain_rows_out=on;
+create table tt (a int, b int) distributed by(a, b);
+explain(costs off, summary off, timing off, analyze)
+insert into tt select * from generate_series(1,1000)a,generate_series(1,1000)b;
+                                                                    QUERY PLAN                                                                    
+--------------------------------------------------------------------------------------------------------------------------------------------------
+ Insert on tt (actual rows=0 loops=1)
+   Rows out: 0.00 rows avg x 0 workers from 3 segments, 0 rows max (seg0 worker0), 0 rows min (seg0 worker0).
+   ->  Redistribute Motion 1:3  (slice1; segments: 1) (actual rows=333518 loops=1)
+         Hash Key: a.a, b.b
+         Rows out: 333333.33 rows avg x 3 workers from 3 segments, 333518 rows max (seg2 worker2), 333150 rows min (seg1 worker1).
+         ->  Nested Loop (actual rows=1000000 loops=1)
+               Rows out: 1000000.00 rows avg x 1 workers from 1 segments, 1000000 rows max (seg2 worker0), 1000000 rows min (seg2 worker0).
+               ->  Function Scan on generate_series a (actual rows=1000 loops=1)
+                     Rows out: 1000.00 rows avg x 1 workers from 1 segments, 1000 rows max (seg2 worker0), 1000 rows min (seg2 worker0).
+               ->  Function Scan on generate_series b (actual rows=1000 loops=1000)
+                     Rows out: 1000000.00 rows avg x 1 workers from 1 segments, 1000000 rows max (seg2 worker0), 1000000 rows min (seg2 worker0).
+ Optimizer: Postgres query optimizer
+(12 rows)
+
+explain(costs off, summary off, timing off, analyze)
+select * from tt where a > b;
+                                                            QUERY PLAN                                                             
+-----------------------------------------------------------------------------------------------------------------------------------
+ Gather Motion 3:1  (slice1; segments: 3) (actual rows=499500 loops=1)
+   Rows out: 499500.00 rows avg x 1 workers from 1 segments, 499500 rows max (seg-1 worker0), 499500 rows min (seg-1 worker0).
+   ->  Seq Scan on tt (actual rows=166461 loops=1)
+         Filter: (a > b)
+         Rows Removed by Filter: 167057
+         Rows out: 166500.00 rows avg x 3 workers from 3 segments, 166557 rows max (seg0 worker0), 166461 rows min (seg2 worker2).
+ Optimizer: Postgres query optimizer
+(7 rows)
+
+abort;
 --
 -- Test GPDB-specific EXPLAIN (SLICETABLE) option.
 --

src/test/regress/expected/gp_explain_optimizer.out

@@ -458,6 +458,42 @@ explain analyze SELECT * FROM explaintest;
 (8 rows)
 
 set gp_enable_explain_allstat=DEFAULT;
+-- Test explain rows out.
+begin;
+set local gp_enable_explain_rows_out=on;
+create table tt (a int, b int) distributed by(a, b);
+explain(costs off, summary off, timing off, analyze)
+insert into tt select * from generate_series(1,1000)a,generate_series(1,1000)b;
+                                                                    QUERY PLAN                                                                    
+--------------------------------------------------------------------------------------------------------------------------------------------------
+ Insert on tt (actual rows=0 loops=1)
+   Rows out: 0.00 rows avg x 0 workers from 3 segments, 0 rows max (seg0 worker0), 0 rows min (seg0 worker0).
+   ->  Redistribute Motion 1:3  (slice1; segments: 1) (actual rows=333518 loops=1)
+         Hash Key: a.a, b.b
+         Rows out: 333333.33 rows avg x 3 workers from 3 segments, 333518 rows max (seg2 worker2), 333150 rows min (seg1 worker1).
+         ->  Nested Loop (actual rows=1000000 loops=1)
+               Rows out: 1000000.00 rows avg x 1 workers from 1 segments, 1000000 rows max (seg2 worker0), 1000000 rows min (seg2 worker0).
+               ->  Function Scan on generate_series a (actual rows=1000 loops=1)
+                     Rows out: 1000.00 rows avg x 1 workers from 1 segments, 1000 rows max (seg2 worker0), 1000 rows min (seg2 worker0).
+               ->  Function Scan on generate_series b (actual rows=1000 loops=1000)
+                     Rows out: 1000000.00 rows avg x 1 workers from 1 segments, 1000000 rows max (seg2 worker0), 1000000 rows min (seg2 worker0).
+ Optimizer: Postgres query optimizer
+(12 rows)
+
+explain(costs off, summary off, timing off, analyze)
+select * from tt where a > b;
+                                                            QUERY PLAN                                                             
+-----------------------------------------------------------------------------------------------------------------------------------
+ Gather Motion 3:1  (slice1; segments: 3) (actual rows=499500 loops=1)
+   Rows out: 499500.00 rows avg x 1 workers from 1 segments, 499500 rows max (seg-1 worker0), 499500 rows min (seg-1 worker0).
+   ->  Seq Scan on tt (actual rows=166461 loops=1)
+         Filter: (a > b)
+         Rows Removed by Filter: 167057
+         Rows out: 166500.00 rows avg x 3 workers from 3 segments, 166557 rows max (seg0 worker0), 166461 rows min (seg2 worker2).
+ Optimizer: Postgres query optimizer
+(7 rows)
+
+abort;
 --
 -- Test GPDB-specific EXPLAIN (SLICETABLE) option.
 --

src/test/regress/sql/cbdb_parallel.sql

@@ -986,6 +986,24 @@ select t1_anti.a, t1_anti.b from t1_anti left join t2_anti on t1_anti.a = t2_ant
 select t1_anti.a, t1_anti.b from t1_anti left join t2_anti on t1_anti.a = t2_anti.a where t2_anti.a is null;
 abort;
 
+-- test rows out
+-- start_matchsubs
+-- m/\(actual rows=\d+ loops=\d+\)/
+-- s/\(actual rows=\d+ loops=\d+\)/(actual rows=# loops=#)/
+-- m/Rows Removed by Filter: \d+/
+-- s/Rows Removed by Filter: \d+/Rows Removed by Filter: ###/
+-- m/\d+ rows max \(seg\d+ worker\d+\), \d+ rows min \(seg\d+ worker\d+\)/
+-- s/\d+ rows max \(seg\d+ worker\d+\), \d+ rows min \(seg\d+ worker\d+\)/##### rows max (seg# worker#), ##### rows min (seg# worker#)/
+-- end_matchsubs
+begin;
+create table tt (a int, b int) with(parallel_workers=2) distributed by(a, b);
+insert into tt select * from generate_series(1,1000)a,generate_series(1,1000)b;
+set local enable_parallel = on;
+set local max_parallel_workers_per_gather = 2;
+set local gp_enable_explain_rows_out = on;
+explain(costs off, summary off, timing off, analyze) select * from tt where a > b;
+abort;
+
 -- start_ignore
 drop schema test_parallel cascade;
 -- end_ignore

src/test/regress/sql/gp_explain.sql

@@ -228,6 +228,16 @@ set gp_enable_explain_allstat=on;
 explain analyze SELECT * FROM explaintest;
 set gp_enable_explain_allstat=DEFAULT;
 
+-- Test explain rows out.
+begin;
+set local gp_enable_explain_rows_out=on;
+create table tt (a int, b int) distributed by(a, b);
+explain(costs off, summary off, timing off, analyze)
+insert into tt select * from generate_series(1,1000)a,generate_series(1,1000)b;
+explain(costs off, summary off, timing off, analyze)
+select * from tt where a > b;
+abort;
+
 
 --
 -- Test GPDB-specific EXPLAIN (SLICETABLE) option.