Use ChunkAppend when the path is parameterized with clauses and not ordered

If it's parameterized with clauses, there's opportunity to use runtime
chunk exclusion.

Author: akuzm

src/planner/planner.c

@@ -1018,16 +1018,34 @@ static inline bool
 should_chunk_append(Hypertable *ht, PlannerInfo *root, RelOptInfo *rel, Path *path, bool ordered,
 					int order_attno)
 {
-	if (path->param_info != NULL && ordered)
+	if (path->param_info != NULL)
 	{
+		if (ordered)
+		{
+			/*
+			 * Ordered ChunkAppend might create MergeAppend path for individual
+			 * chunks when we have space partitioning or partial chunks. MergeAppend
+			 * paths cannot be parameterized. Refuse to use parameterized ordered
+			 * ChunkAppend altogether, because the more precise conditions are
+			 * difficult to check.
+			 */
+			return false;
+		}
+
+		if (path->param_info->ppi_clauses != NIL)
+		{
+			/*
+			 * If we have any parameterized clauses, we can apply runtime chunk
+			 * exclusion.
+			 */
+			return true;
+		}
+
 		/*
-		 * Ordered ChunkAppend might create MergeAppend path for individual
-		 * chunks when we have space partitioning or partial chunks. MergeAppend
-		 * paths cannot be parameterized. Refuse to use parameterized ordered
-		 * ChunkAppend altogether, because the more precise conditions are
-		 * difficult to check.
+		 * The path can be parameterized but not have any parameterized clauses,
+		 * effectively if it's a cross join written as LATERAL. Check the other
+		 * conditions for chunk append in this case.
 		 */
-		return false;
 	}
 
 	if (

tsl/test/shared/expected/parameterized_chunkappend-17.out

@@ -43,6 +43,33 @@ ORDER BY devices.device_id, win.id
                            ->  Index Only Scan using _hyper_X_X_chunk_metrics_device_id_time_idx on _hyper_X_X_chunk (actual rows=360.00 loops=3)
                                  Index Cond: ((device_id = devices.device_id) AND ("time" >= "*VALUES*".column2) AND ("time" < "*VALUES*".column3) AND ("time" > (now() - '@ 100 years'::interval)))
 
+:PREFIX
+SELECT time FROM unnest(array['2000-01-10 1:00+0'::timestamptz]) AS vars(v)
+JOIN metrics ON time = vars.v;
+--- QUERY PLAN ---
+ Nested Loop (actual rows=5.00 loops=1)
+   ->  Function Scan on unnest vars (actual rows=1.00 loops=1)
+   ->  Custom Scan (ChunkAppend) on metrics (actual rows=5.00 loops=1)
+         Chunks excluded during runtime: 2
+         ->  Index Only Scan using _hyper_X_X_chunk_metrics_time_idx on _hyper_X_X_chunk (never executed)
+               Index Cond: ("time" = vars.v)
+         ->  Index Only Scan using _hyper_X_X_chunk_metrics_time_idx on _hyper_X_X_chunk (actual rows=5.00 loops=1)
+               Index Cond: ("time" = vars.v)
+         ->  Index Only Scan using _hyper_X_X_chunk_metrics_time_idx on _hyper_X_X_chunk (never executed)
+               Index Cond: ("time" = vars.v)
+
+:PREFIX
+SELECT count(s.w) FROM unnest(array[1]::int[]) AS vars(v)
+LEFT JOIN LATERAL (SELECT vars.v AS w FROM metrics) s ON true;
+--- QUERY PLAN ---
+ Aggregate (actual rows=1.00 loops=1)
+   ->  Nested Loop Left Join (actual rows=68370.00 loops=1)
+         ->  Function Scan on unnest vars (actual rows=1.00 loops=1)
+         ->  Append (actual rows=68370.00 loops=1)
+               ->  Seq Scan on _hyper_X_X_chunk (actual rows=17990.00 loops=1)
+               ->  Seq Scan on _hyper_X_X_chunk (actual rows=25190.00 loops=1)
+               ->  Seq Scan on _hyper_X_X_chunk (actual rows=25190.00 loops=1)
+
 RESET enable_hashjoin;
 RESET enable_mergejoin;
 RESET enable_material;

tsl/test/shared/sql/parameterized_chunkappend.sql.in

@@ -28,10 +28,20 @@ GROUP BY devices.device_id, win.id
 ORDER BY devices.device_id, win.id
 ;
 
+:PREFIX
+SELECT time FROM unnest(array['2000-01-10 1:00+0'::timestamptz]) AS vars(v)
+JOIN metrics ON time = vars.v;
+
+:PREFIX
+SELECT count(s.w) FROM unnest(array[1]::int[]) AS vars(v)
+LEFT JOIN LATERAL (SELECT vars.v AS w FROM metrics) s ON true;
+
+
 RESET enable_hashjoin;
 RESET enable_mergejoin;
 RESET enable_material;
 
+
 -- #9607: PlaceHolderVar in runtime chunk exclusion clauses used to trip
 -- pull_var_clause with flag 0. GROUP BY ROLLUP on a view over a hypertable
 -- combined with a join and a generic plan can produce such PlaceHolderVars.