Fix delete on tables involving hypertables with compression

The DML blocker to block INSERTs and UPDATEs on compressed hypertables
would trigger if the UPDATE or DELETE referenced any hypertable with
compressed chunks. This patch changes the logic to only block if the
target of the UPDATE or DELETE is a compressed hypertable.

src/planner.c

@@ -726,6 +726,18 @@ valid_hook_call(void)
 	return ts_extension_is_loaded() && planner_hcache_exists();
 }
 
+static bool
+dml_involves_hypertable(PlannerInfo *root, Hypertable *ht, Index rti)
+{
+	Index result_rti = root->parse->resultRelation;
+	RangeTblEntry *result_rte = root->simple_rte_array[result_rti];
+
+	if (result_rti == rti || ht->main_table_relid == result_rte->relid)
+		return true;
+
+	return false;
+}
+
 static void
 timescaledb_set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
 {
@@ -763,7 +775,7 @@ timescaledb_set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, Rang
 		case TS_REL_CHUNK:
 		case TS_REL_CHUNK_CHILD:
 			/* Check for UPDATE/DELETE (DLM) on compressed chunks */
-			if (IS_UPDL_CMD(root->parse))
+			if (IS_UPDL_CMD(root->parse) && dml_involves_hypertable(root, ht, rti))
 			{
 				if (ts_cm_functions->set_rel_pathlist_dml != NULL)
 					ts_cm_functions->set_rel_pathlist_dml(root, rel, rti, rte, ht);

tsl/src/nodes/decompress_chunk/exec.c

@@ -188,8 +188,10 @@ constify_tableoid_walker(Node *node, ConstifyTableOidContext *ctx)
 		 * we doublecheck system columns here because projection will
 		 * segfault if any system columns get through
 		 */
-		if (var->varattno < 0)
-			elog(ERROR, "transparent decompression only supports tableoid system column");
+		if (var->varattno < SelfItemPointerAttributeNumber)
+			elog(ERROR,
+				 "transparent decompression only supports tableoid system column %d",
+				 var->varattno);
 
 		return node;
 	}

tsl/test/expected/compression.out

@@ -1124,3 +1124,58 @@ ERROR:  constraint "fk_table1" requires column "col2" to be a timescaledb.compre
 ALTER TABLE table1 SET (timescaledb.compress, timescaledb.compress_segmentby = 'col1,col2');
 NOTICE:  adding index _compressed_hypertable_23_col1__ts_meta_sequence_num_idx ON _timescaledb_internal._compressed_hypertable_23 USING BTREE(col1, _ts_meta_sequence_num)
 NOTICE:  adding index _compressed_hypertable_23_col2__ts_meta_sequence_num_idx ON _timescaledb_internal._compressed_hypertable_23 USING BTREE(col2, _ts_meta_sequence_num)
+-- test delete non-compressed tables involving hypertables with compression
+CREATE TABLE delete_ht1 (
+    time timestamptz NOT NULL,
+    value double precision,
+    series_id integer
+);
+SELECT table_name FROM create_hypertable ('delete_ht1', 'time');
+ table_name 
+------------
+ delete_ht1
+(1 row)
+
+INSERT INTO delete_ht1
+    VALUES ('2020-04-20 01:01', 100, 1), ('2020-05-20 01:01', 100, 1), ('2020-04-20 01:01', 200, 2);
+CREATE TABLE delete_ht2 (
+    time timestamptz NOT NULL,
+    value double precision,
+    series_id integer
+);
+SELECT table_name FROM create_hypertable ('delete_ht2', 'time');
+ table_name 
+------------
+ delete_ht2
+(1 row)
+
+ALTER TABLE delete_ht2 SET (timescaledb.compress);
+INSERT INTO delete_ht2
+    VALUES ('2020-04-20 01:01', 100, 1), ('2020-05-20 01:01', 100, 1);
+SELECT
+    compress_chunk (ch1.schema_name || '.' || ch1.table_name)
+FROM
+    _timescaledb_catalog.chunk ch1,
+    _timescaledb_catalog.hypertable ht
+WHERE
+    ch1.hypertable_id = ht.id
+    AND ht.table_name LIKE 'delete_ht2'
+ORDER BY
+    ch1.id;
+              compress_chunk              
+------------------------------------------
+ _timescaledb_internal._hyper_25_51_chunk
+ _timescaledb_internal._hyper_25_52_chunk
+(2 rows)
+
+WITH confirmed_drop_series AS (
+    SELECT
+        series_id
+    FROM
+        delete_ht2 data_exists
+    WHERE
+        time >= '2020-04-17 17:14:24.161989+00'
+)
+DELETE FROM delete_ht1
+WHERE
+    series_id IN (SELECT series_id FROM confirmed_drop_series);

tsl/test/sql/compression.sql

@@ -452,3 +452,51 @@ ALTER TABLE table1 SET (timescaledb.compress, timescaledb.compress_segmentby = '
 -- Listing all fields of the compound key should succeed:
 ALTER TABLE table1 SET (timescaledb.compress, timescaledb.compress_segmentby = 'col1,col2');
 
+-- test delete non-compressed tables involving hypertables with compression
+CREATE TABLE delete_ht1 (
+    time timestamptz NOT NULL,
+    value double precision,
+    series_id integer
+);
+
+SELECT table_name FROM create_hypertable ('delete_ht1', 'time');
+
+INSERT INTO delete_ht1
+    VALUES ('2020-04-20 01:01', 100, 1), ('2020-05-20 01:01', 100, 1), ('2020-04-20 01:01', 200, 2);
+
+CREATE TABLE delete_ht2 (
+    time timestamptz NOT NULL,
+    value double precision,
+    series_id integer
+);
+
+SELECT table_name FROM create_hypertable ('delete_ht2', 'time');
+
+ALTER TABLE delete_ht2 SET (timescaledb.compress);
+
+INSERT INTO delete_ht2
+    VALUES ('2020-04-20 01:01', 100, 1), ('2020-05-20 01:01', 100, 1);
+
+SELECT
+    compress_chunk (ch1.schema_name || '.' || ch1.table_name)
+FROM
+    _timescaledb_catalog.chunk ch1,
+    _timescaledb_catalog.hypertable ht
+WHERE
+    ch1.hypertable_id = ht.id
+    AND ht.table_name LIKE 'delete_ht2'
+ORDER BY
+    ch1.id;
+
+WITH confirmed_drop_series AS (
+    SELECT
+        series_id
+    FROM
+        delete_ht2 data_exists
+    WHERE
+        time >= '2020-04-17 17:14:24.161989+00'
+)
+DELETE FROM delete_ht1
+WHERE
+    series_id IN (SELECT series_id FROM confirmed_drop_series);
+