Further work

src/planner/expand_hypertable.c

@@ -1417,7 +1417,8 @@ ts_plan_expand_hypertable_chunks(Hypertable *ht, PlannerInfo *root, RelOptInfo *
 	 * partitionwise aggregation. */
 
 	if ((ts_guc_enable_partitionwise_aggregation &&
-		 !has_partialize_function((Node *) root->parse->targetList, TS_DO_NOT_FIX_AGGSPLIT) && num_chunks > 0) ||
+		 !has_partialize_function((Node *) root->parse->targetList, TS_DO_NOT_FIX_AGGSPLIT) &&
+		 num_chunks > 0) ||
 		hypertable_is_distributed(ht))
 	{
 		enable_partitionwise_aggregate = true; // FIXME

src/planner/planner.c

@@ -1512,11 +1512,6 @@ replace_hypertable_modify_paths(PlannerInfo *root, List *pathlist, RelOptInfo *i
 	return new_pathlist;
 }
 
-static void
-create_vector_paths(PlannerInfo *root, List *pathlist)
-{
-}
-
 static void
 timescaledb_create_upper_paths_hook(PlannerInfo *root, UpperRelationKind stage,
 									RelOptInfo *input_rel, RelOptInfo *output_rel, void *extra)
@@ -1568,8 +1563,6 @@ timescaledb_create_upper_paths_hook(PlannerInfo *root, UpperRelationKind stage,
 
 		if (parse->hasAggs)
 			ts_preprocess_first_last_aggregates(root, root->processed_tlist);
-
-		create_vector_paths(root, output_rel->pathlist);
 	}
 }
 

tsl/src/nodes/CMakeLists.txt

@@ -5,6 +5,7 @@ set(SOURCES
 target_sources(${TSL_LIBRARY_NAME} PRIVATE ${SOURCES})
 add_subdirectory(compress_dml)
 add_subdirectory(decompress_chunk)
+add_subdirectory(decompress_chunk_vector)
 add_subdirectory(frozen_chunk_dml)
 add_subdirectory(gapfill)
 add_subdirectory(skip_scan)

tsl/src/nodes/decompress_chunk/decompress_chunk.c

@@ -801,7 +801,6 @@ ts_decompress_chunk_generate_paths(PlannerInfo *root, RelOptInfo *chunk_rel, Hyp
 					continue;
 			}
 
-
 			// make make_partition_pruneinfo() happy
 			root->append_rel_array[info->compressed_rel->relid] =
 				root->append_rel_array[info->chunk_rel->relid];

tsl/src/nodes/decompress_chunk_vector/CMakeLists.txt

@@ -0,0 +1,3 @@
+# Add all *.c to sources in upperlevel directory
+set(SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/decompress_chunk_vector.c)
+target_sources(${TSL_LIBRARY_NAME} PRIVATE ${SOURCES})

tsl/src/nodes/decompress_chunk_vector/decompress_chunk_vector.c

@@ -0,0 +1,59 @@
+/*
+ * This file and its contents are licensed under the Timescale License.
+ * Please see the included NOTICE for copyright information and
+ * LICENSE-TIMESCALE for a copy of the license.
+ */
+
+#include <postgres.h>
+#include <catalog/pg_operator.h>
+#include <miscadmin.h>
+#include <nodes/bitmapset.h>
+#include <nodes/makefuncs.h>
+#include <nodes/nodeFuncs.h>
+#include <optimizer/cost.h>
+#include <optimizer/optimizer.h>
+#include <optimizer/pathnode.h>
+#include <optimizer/paths.h>
+#include <parser/parsetree.h>
+#include <utils/builtins.h>
+#include <utils/lsyscache.h>
+#include <utils/typcache.h>
+
+#include <planner.h>
+
+#include "compat/compat.h"
+#include "debug_assert.h"
+#include "ts_catalog/hypertable_compression.h"
+#include "import/planner.h"
+#include "compression/create.h"
+#include "nodes/decompress_chunk/decompress_chunk.h"
+#include "nodes/decompress_chunk/planner.h"
+#include "nodes/decompress_chunk/qual_pushdown.h"
+#include "nodes/decompress_chunk_vector/decompress_chunk_vector.h"
+#include "utils.h"
+
+void
+ts_decompress_vector_modify_paths(PlannerInfo *root, RelOptInfo *input_rel, RelOptInfo *output_rel)
+{
+	Assert(root != NULL);
+	Assert(input_rel != NULL);
+	Assert(output_rel != NULL);
+	Assert(output_rel->reloptkind == RELOPT_UPPER_REL);
+
+	ListCell *lc;
+	foreach (lc, output_rel->pathlist)
+	{
+		/* We are only interested in AggPaths */
+		if (!IsA(lfirst(lc), AggPath))
+			continue;
+
+		AggPath *aggregation_path = lfirst_node(AggPath, lc);
+
+		/* We are only interested in splitted paths */
+		if (aggregation_path->aggsplit != AGGSPLIT_FINAL_DESERIAL)
+			continue;
+
+		Path *aggregation_sub_path = aggregation_path->subpath;
+		Assert(aggregation_sub_path);
+	}
+}

tsl/src/nodes/decompress_chunk_vector/decompress_chunk_vector.h

@@ -0,0 +1,19 @@
+/*
+ * This file and its contents are licensed under the Timescale License.
+ * Please see the included NOTICE for copyright information and
+ * LICENSE-TIMESCALE for a copy of the license.
+ */
+#ifndef TIMESCALEDB_DECOMPRESS_CHUNK_VECTOR_H
+#define TIMESCALEDB_DECOMPRESS_CHUNK_VECTOR_H
+
+#include <postgres.h>
+#include <nodes/bitmapset.h>
+#include <nodes/extensible.h>
+
+#include "chunk.h"
+#include "hypertable.h"
+
+extern void ts_decompress_vector_modify_paths(PlannerInfo *root, RelOptInfo *input_rel,
+											  RelOptInfo *output_rel);
+
+#endif

tsl/src/planner.c

@@ -27,6 +27,7 @@
 #include "nodes/compress_dml/compress_dml.h"
 #include "nodes/frozen_chunk_dml/frozen_chunk_dml.h"
 #include "nodes/decompress_chunk/decompress_chunk.h"
+#include "nodes/decompress_chunk_vector/decompress_chunk_vector.h"
 #include "nodes/data_node_dispatch.h"
 #include "nodes/data_node_copy.h"
 #include "nodes/gapfill/gapfill.h"
@@ -91,6 +92,10 @@ tsl_create_upper_paths_hook(PlannerInfo *root, UpperRelationKind stage, RelOptIn
 		case UPPERREL_GROUP_AGG:
 			if (input_reltype != TS_REL_HYPERTABLE_CHILD)
 				plan_add_gapfill(root, output_rel);
+
+			if (output_rel != NULL)
+				ts_decompress_vector_modify_paths(root, input_rel, output_rel);
+
 			break;
 		case UPPERREL_WINDOW:
 			if (IsA(linitial(input_rel->pathlist), CustomPath))