Add GUC to enable/disable DML decompression

src/guc.c

@@ -75,6 +75,7 @@ bool ts_guc_enable_qual_propagation = true;
 bool ts_guc_enable_cagg_reorder_groupby = true;
 bool ts_guc_enable_now_constify = true;
 bool ts_guc_enable_osm_reads = true;
+TSDLLEXPORT bool ts_guc_enable_dml_decompression = true;
 TSDLLEXPORT bool ts_guc_enable_transparent_decompression = true;
 TSDLLEXPORT bool ts_guc_enable_decompression_sorted_merge = true;
 bool ts_guc_enable_per_data_node_queries = true;
@@ -269,6 +270,17 @@ _guc_init(void)
 							 NULL,
 							 NULL);
 
+	DefineCustomBoolVariable("timescaledb.enable_dml_decompression",
+							 "Enable DML decompression",
+							 "Enable DML decompression when modifying compressed hypertable",
+							 &ts_guc_enable_dml_decompression,
+							 true,
+							 PGC_USERSET,
+							 0,
+							 NULL,
+							 NULL,
+							 NULL);
+
 	DefineCustomBoolVariable("timescaledb.enable_transparent_decompression",
 							 "Enable transparent decompression",
 							 "Enable transparent decompression when querying hypertable",

src/guc.h

@@ -26,6 +26,7 @@ extern bool ts_guc_enable_constraint_exclusion;
 extern bool ts_guc_enable_cagg_reorder_groupby;
 extern bool ts_guc_enable_now_constify;
 extern bool ts_guc_enable_osm_reads;
+extern TSDLLEXPORT bool ts_guc_enable_dml_decompression;
 extern TSDLLEXPORT bool ts_guc_enable_transparent_decompression;
 extern TSDLLEXPORT bool ts_guc_enable_decompression_sorted_merge;
 extern TSDLLEXPORT bool ts_guc_enable_per_data_node_queries;

src/planner/planner.c

@@ -1339,7 +1339,7 @@ timescaledb_get_relation_info_hook(PlannerInfo *root, Oid relation_objectid, boo
 				RangeTblEntry *chunk_rte = planner_rt_fetch(rel->relid, root);
 				Chunk *chunk = ts_chunk_get_by_relid(chunk_rte->relid, true);
 
-				if (chunk->fd.compressed_chunk_id > 0)
+				if (chunk->fd.compressed_chunk_id != INVALID_CHUNK_ID)
 				{
 					Relation uncompressed_chunk = table_open(relation_objectid, NoLock);
 

tsl/src/compression/compression.c

@@ -1957,6 +1957,12 @@ decompress_batches_for_insert(ChunkInsertState *cis, Chunk *chunk, TupleTableSlo
 		return;
 	}
 
+	if (!ts_guc_enable_dml_decompression)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("inserting into compressed chunk with unique constraints disabled"),
+				 errhint("Set timescaledb.enable_dml_decompression to TRUE.")));
+
 	Chunk *comp = ts_chunk_get_by_id(chunk->fd.compressed_chunk_id, true);
 	Relation in_rel = relation_open(comp->table_id, RowExclusiveLock);
 
@@ -2470,6 +2476,12 @@ decompress_chunk_walker(PlanState *ps, List *relids)
 			current_chunk = ts_chunk_get_by_relid(rte->relid, false);
 			if (current_chunk && ts_chunk_is_compressed(current_chunk))
 			{
+				if (!ts_guc_enable_dml_decompression)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("UPDATE/DELETE is disabled on compressed chunks"),
+							 errhint("Set timescaledb.enable_dml_decompression to TRUE.")));
+
 				decompress_batches_for_update_delete(current_chunk, predicates);
 			}
 		}

tsl/src/nodes/compress_dml/compress_dml.c

@@ -84,7 +84,6 @@ compress_chunk_dml_exec(CustomScanState *node)
 static void
 compress_chunk_dml_end(CustomScanState *node)
 {
-	// CompressChunkDmlState *state = (CompressChunkDmlState *) node;
 	PlanState *substate = linitial(node->custom_ps);
 	ExecEndNode(substate);
 }
@@ -99,7 +98,6 @@ compress_chunk_dml_path_create(Path *subpath, Oid chunk_relid)
 	path->cpath.path.pathtype = T_CustomScan;
 	path->cpath.path.parent = subpath->parent;
 	path->cpath.path.pathtarget = subpath->pathtarget;
-	// path->cpath.path.param_info = subpath->param_info;
 	path->cpath.methods = &compress_chunk_dml_path_methods;
 	path->cpath.custom_paths = list_make1(subpath);
 	path->chunk_relid = chunk_relid;
@@ -139,6 +137,6 @@ compress_chunk_dml_state_create(CustomScan *scan)
 Path *
 compress_chunk_dml_generate_paths(Path *subpath, Chunk *chunk)
 {
-	Assert(chunk->fd.compressed_chunk_id > 0);
+	Assert(chunk->fd.compressed_chunk_id != INVALID_CHUNK_ID);
 	return compress_chunk_dml_path_create(subpath, chunk->table_id);
 }

tsl/src/planner.c

@@ -129,7 +129,7 @@ tsl_set_rel_pathlist_query(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeT
 	{
 		Chunk *chunk = ts_chunk_get_by_relid(rte->relid, true);
 
-		if (chunk->fd.compressed_chunk_id > 0)
+		if (chunk->fd.compressed_chunk_id != INVALID_CHUNK_ID)
 			ts_decompress_chunk_generate_paths(root, rel, ht, chunk);
 	}
 }
@@ -163,7 +163,7 @@ tsl_set_rel_pathlist_dml(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTbl
 	{
 		ListCell *lc;
 		Chunk *chunk = ts_chunk_get_by_relid(rte->relid, true);
-		if (chunk->fd.compressed_chunk_id > 0)
+		if (chunk->fd.compressed_chunk_id != INVALID_CHUNK_ID)
 		{
 			foreach (lc, rel->pathlist)
 			{

tsl/test/expected/compression_conflicts.out

@@ -493,3 +493,25 @@ WHERE hypertable_name = 'compressed_ht' ORDER BY chunk_name;
             9 | _hyper_9_9_chunk
 (3 rows)
 
+-- test for disabling DML decompression
+SHOW timescaledb.enable_dml_decompression;
+ timescaledb.enable_dml_decompression 
+--------------------------------------
+ on
+(1 row)
+
+SET timescaledb.enable_dml_decompression = false;
+\set ON_ERROR_STOP 0
+-- Should error because we disabled the DML decompression
+INSERT INTO compressed_ht VALUES ('2022-01-24 01:10:28.192199+05:30', '6', 0.876, 4.123, 'new insert row')
+  ON conflict(sensor_id, time)
+DO UPDATE SET sensor_id = excluded.sensor_id , name = 'ON CONFLICT DO UPDATE' RETURNING *;
+ERROR:  inserting into compressed chunk with unique constraints disabled
+INSERT INTO compressed_ht VALUES ('2022-01-24 01:10:28.192199+05:30', '6', 0.876, 4.123, 'new insert row')
+  ON conflict(sensor_id, time)
+DO NOTHING;
+ERROR:  inserting into compressed chunk with unique constraints disabled
+-- Even a regular insert will fail due to unique constrant checks for dml decompression
+INSERT INTO compressed_ht VALUES ('2022-01-24 01:10:28.192199+05:30', '7', 0.876, 4.123, 'new insert row');
+ERROR:  inserting into compressed chunk with unique constraints disabled
+\set ON_ERROR_STOP 1

tsl/test/expected/compression_update_delete.out

@@ -31,7 +31,7 @@ WARNING:  column type "character varying" used for "name" does not follow best p
              1 | public      | sample_table | t
 (1 row)
 
-SELECT '2022-01-28 01:09:53.583252+05:30' as start_date \gset
+\set start_date '2022-01-28 01:09:53.583252+05:30'
 INSERT INTO sample_table
     SELECT
        	time + (INTERVAL '1 minute' * random()) AS time,
@@ -45,7 +45,7 @@ INSERT INTO sample_table
        		generate_series(1, 8, 1 ) AS g2(sensor_id)
        	ORDER BY
        		time;
-SELECT '2023-03-17 17:51:11.322998+05:30' as start_date \gset
+\set start_date '2023-03-17 17:51:11.322998+05:30'
 -- insert into new chunks
 INSERT INTO sample_table VALUES (:'start_date'::timestamptz, 12, 21.98, 33.123, 'new row1');
 INSERT INTO sample_table VALUES (:'start_date'::timestamptz, 12, 17.66, 13.875, 'new row1');
@@ -1274,7 +1274,7 @@ SELECT COUNT(*) FROM :COMPRESS_CHUNK_1 WHERE c4 IS NULL;
 DROP TABLE sample_table;
 -- test filtering with ORDER BY columns
 CREATE TABLE sample_table(time timestamptz, c1 int, c2 int, c3 int, c4 int);
-SELECT create_hypertable('sample_table','time');
+SELECT create_hypertable('sample_table','time',chunk_time_interval=>'1 day'::interval);
 NOTICE:  adding not-null constraint to column "time"
      create_hypertable      
 ----------------------------
@@ -1301,12 +1301,12 @@ SELECT compress_chunk(show_chunks('sample_table'));
 SELECT ch1.schema_name|| '.' || ch1.table_name AS "CHUNK_1"
 FROM _timescaledb_catalog.chunk ch1, _timescaledb_catalog.hypertable ht
 WHERE ch1.hypertable_id = ht.id AND ch1.table_name LIKE '_hyper_%'
-ORDER BY ch1.id \gset
+ORDER BY ch1.id LIMIT 1 \gset
 -- get FIRST compressed chunk
 SELECT ch1.schema_name|| '.' || ch1.table_name AS "COMPRESS_CHUNK_1"
 FROM _timescaledb_catalog.chunk ch1, _timescaledb_catalog.hypertable ht
 WHERE ch1.hypertable_id = ht.id AND ch1.table_name LIKE 'compress_%'
-ORDER BY ch1.id \gset
+ORDER BY ch1.id LIMIT 1 \gset
 -- check that you uncompress and delete only for exact SEGMENTBY value
 BEGIN;
 -- report 10 rows
@@ -2122,3 +2122,128 @@ SELECT count(*) FROM :COMP_CHUNK_1 WHERE device_id = 2 AND _ts_meta_max_1 >= '20
 (1 row)
 
 ROLLBACK;
+-- test for disabling DML decompression
+SHOW timescaledb.enable_dml_decompression;
+ timescaledb.enable_dml_decompression 
+--------------------------------------
+ on
+(1 row)
+
+SET timescaledb.enable_dml_decompression = false;
+\set ON_ERROR_STOP 0
+-- should ERROR both UPDATE/DELETE statements because the DML decompression is disabled
+UPDATE sample_table SET c3 = NULL WHERE c4 = 5;
+ERROR:  UPDATE/DELETE is disabled on compressed chunks
+DELETE FROM sample_table WHERE c4 = 5;
+ERROR:  UPDATE/DELETE is disabled on compressed chunks
+\set ON_ERROR_STOP 1
+-- make sure reseting the GUC we will be able to UPDATE/DELETE compressed chunks
+RESET timescaledb.enable_dml_decompression;
+SHOW timescaledb.enable_dml_decompression;
+ timescaledb.enable_dml_decompression 
+--------------------------------------
+ on
+(1 row)
+
+BEGIN;
+-- report 0 rows
+SELECT count(*) FROM sample_table WHERE c4 = 5 AND c3 IS NULL;
+ count 
+-------
+     0
+(1 row)
+
+UPDATE sample_table SET c3 = NULL WHERE c4 = 5;
+-- report 10k rows
+SELECT count(*) FROM sample_table WHERE c4 = 5 AND c3 IS NULL;
+ count 
+-------
+ 10000
+(1 row)
+
+ROLLBACK;
+BEGIN;
+-- report 10k rows
+SELECT count(*) FROM sample_table WHERE c4 = 5;
+ count 
+-------
+ 10000
+(1 row)
+
+DELETE FROM sample_table WHERE c4 = 5;
+-- report 0 rows
+SELECT count(*) FROM sample_table WHERE c4 = 5;
+ count 
+-------
+     0
+(1 row)
+
+ROLLBACK;
+-- create new uncompressed chunk
+INSERT INTO sample_table
+SELECT t, 1, 1, 1, 1
+FROM generate_series('2023-05-04 00:00:00-00'::timestamptz,
+            '2023-05-04 00:00:00-00'::timestamptz + INTERVAL '2 hours',
+            INTERVAL '1 hour') t;
+-- check chunk compression status
+SELECT chunk_name, is_compressed
+FROM timescaledb_information.chunks
+WHERE hypertable_name = 'sample_table'
+ORDER BY chunk_name;
+     chunk_name     | is_compressed 
+--------------------+---------------
+ _hyper_19_37_chunk | t
+ _hyper_19_61_chunk | f
+(2 rows)
+
+-- test for uncompressed and compressed chunks
+SHOW timescaledb.enable_dml_decompression;
+ timescaledb.enable_dml_decompression 
+--------------------------------------
+ on
+(1 row)
+
+SET timescaledb.enable_dml_decompression = false;
+BEGIN;
+-- report 3 rows
+SELECT count(*) FROM sample_table WHERE time >= '2023-05-04 00:00:00-00'::timestamptz;
+ count 
+-------
+     3
+(1 row)
+
+-- delete from uncompressed chunk should work
+DELETE FROM sample_table WHERE time >= '2023-05-04 00:00:00-00'::timestamptz;
+-- report 0 rows
+SELECT count(*) FROM sample_table WHERE time >= '2023-05-04 00:00:00-00'::timestamptz;
+ count 
+-------
+     0
+(1 row)
+
+ROLLBACK;
+BEGIN;
+-- report 0 rows
+SELECT count(*) FROM sample_table WHERE time >= '2023-05-04 00:00:00-00'::timestamptz AND c3 IS NULL;
+ count 
+-------
+     0
+(1 row)
+
+UPDATE sample_table SET c3 = NULL WHERE time >= '2023-05-04 00:00:00-00'::timestamptz;
+-- report 3 rows
+SELECT count(*) FROM sample_table WHERE time >= '2023-05-04 00:00:00-00'::timestamptz AND c3 IS NULL;
+ count 
+-------
+     3
+(1 row)
+
+ROLLBACK;
+\set ON_ERROR_STOP 0
+-- should ERROR both UPDATE/DELETE statements because the DML decompression is disabled
+-- and both statements we're touching compressed and uncompressed chunks
+UPDATE sample_table SET c3 = NULL WHERE time >= '2023-03-17 00:00:00-00'::timestamptz AND c3 IS NULL;
+ERROR:  UPDATE/DELETE is disabled on compressed chunks
+DELETE FROM sample_table WHERE time >= '2023-03-17 00:00:00-00'::timestamptz;
+ERROR:  UPDATE/DELETE is disabled on compressed chunks
+\set ON_ERROR_STOP 1

tsl/test/sql/compression_conflicts.sql

@@ -368,3 +368,21 @@ SELECT chunk_status,
        chunk_name as "CHUNK_NAME"
 FROM compressed_chunk_info_view
 WHERE hypertable_name = 'compressed_ht' ORDER BY chunk_name;
+
+-- test for disabling DML decompression
+SHOW timescaledb.enable_dml_decompression;
+SET timescaledb.enable_dml_decompression = false;
+
+\set ON_ERROR_STOP 0
+-- Should error because we disabled the DML decompression
+INSERT INTO compressed_ht VALUES ('2022-01-24 01:10:28.192199+05:30', '6', 0.876, 4.123, 'new insert row')
+  ON conflict(sensor_id, time)
+DO UPDATE SET sensor_id = excluded.sensor_id , name = 'ON CONFLICT DO UPDATE' RETURNING *;
+
+INSERT INTO compressed_ht VALUES ('2022-01-24 01:10:28.192199+05:30', '6', 0.876, 4.123, 'new insert row')
+  ON conflict(sensor_id, time)
+DO NOTHING;
+
+-- Even a regular insert will fail due to unique constrant checks for dml decompression
+INSERT INTO compressed_ht VALUES ('2022-01-24 01:10:28.192199+05:30', '7', 0.876, 4.123, 'new insert row');
+\set ON_ERROR_STOP 1