Allow SQLValueFunction pushdown into compressed scan

Since all SQLValueFunction are STABLE we can safely push them down into the scan of the compressed chunk. The following expressions are pushed down: - CURRENT_DATE - CURRENT_TIME - CURRENT_TIME(p) - CURRENT_TIMESTAMP - CURRENT_TIMESTAMP(p) - LOCALTIME - LOCALTIME(p) - LOCALTIMESTAMP - LOCALTIMESTAMP(p) - USER - CURRENT_USER - SESSION_USER - CURRENT_CATALOG - CURRENT_SCHEMA
timescale · Dec 19, 2023 · 301612a · 301612a
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diff --git a/.unreleased/pr_6440 b/.unreleased/pr_6440
@@ -0,0 +1 @@
+Implements: #6440 Allow SQLValueFunction pushdown into compressed scan
diff --git a/tsl/src/nodes/decompress_chunk/qual_pushdown.c b/tsl/src/nodes/decompress_chunk/qual_pushdown.c
@@ -354,6 +354,7 @@ modify_expression(Node *node, QualPushdownContext *context)
 		case T_Const:
 		case T_NullTest:
 		case T_Param:
+		case T_SQLValueFunction:
 			break;
 		case T_Var:
 		{

diff --git a/tsl/test/expected/compression_qualpushdown.out b/tsl/test/expected/compression_qualpushdown.out
@@ -345,3 +345,172 @@ EXPLAIN (costs off) SELECT '1' FROM deleteme_with_bytea WHERE bdata::text = '123
 
 DROP table deleteme;
 DROP table deleteme_with_bytea;
+-- test sqlvaluefunction pushdown
+CREATE TABLE svf_pushdown(time timestamptz, c_date date, c_time time, c_timetz timetz, c_timestamp timestamptz, c_name text);
+SELECT table_name FROM create_hypertable('svf_pushdown', 'time');
+NOTICE:  adding not-null constraint to column "time"
+  table_name  
+--------------
+ svf_pushdown
+(1 row)
+
+ALTER TABLE svf_pushdown SET (timescaledb.compress,timescaledb.compress_segmentby='c_date,c_time, c_timetz,c_timestamp,c_name');
+INSERT INTO svf_pushdown SELECT '2020-01-01';
+SELECT compress_chunk(show_chunks('svf_pushdown'));
+              compress_chunk              
+------------------------------------------
+ _timescaledb_internal._hyper_11_12_chunk
+(1 row)
+
+-- constraints should be pushed down into scan below decompresschunk in all cases
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_date = CURRENT_DATE;
+                                                         QUERY PLAN                                                         
+----------------------------------------------------------------------------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Index Scan using compress_hyper_12_13_chunk__compressed_hypertable_12_c_date_c_t on compress_hyper_12_13_chunk
+               Index Cond: (c_date = CURRENT_DATE)
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timetz = CURRENT_TIME;
+                                                         QUERY PLAN                                                         
+----------------------------------------------------------------------------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Index Scan using compress_hyper_12_13_chunk__compressed_hypertable_12_c_date_c_t on compress_hyper_12_13_chunk
+               Index Cond: (c_timetz = CURRENT_TIME)
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timetz = CURRENT_TIME(1);
+                                                         QUERY PLAN                                                         
+----------------------------------------------------------------------------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Index Scan using compress_hyper_12_13_chunk__compressed_hypertable_12_c_date_c_t on compress_hyper_12_13_chunk
+               Index Cond: (c_timetz = CURRENT_TIME(1))
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timestamp = CURRENT_TIMESTAMP;
+                                                         QUERY PLAN                                                         
+----------------------------------------------------------------------------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Index Scan using compress_hyper_12_13_chunk__compressed_hypertable_12_c_date_c_t on compress_hyper_12_13_chunk
+               Index Cond: (c_timestamp = CURRENT_TIMESTAMP)
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timestamp = CURRENT_TIMESTAMP(1);
+                                                         QUERY PLAN                                                         
+----------------------------------------------------------------------------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Index Scan using compress_hyper_12_13_chunk__compressed_hypertable_12_c_date_c_t on compress_hyper_12_13_chunk
+               Index Cond: (c_timestamp = CURRENT_TIMESTAMP(1))
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_time = LOCALTIME;
+                                                         QUERY PLAN                                                         
+----------------------------------------------------------------------------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Index Scan using compress_hyper_12_13_chunk__compressed_hypertable_12_c_date_c_t on compress_hyper_12_13_chunk
+               Index Cond: (c_time = LOCALTIME)
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_time = LOCALTIME(1);
+                                                         QUERY PLAN                                                         
+----------------------------------------------------------------------------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Index Scan using compress_hyper_12_13_chunk__compressed_hypertable_12_c_date_c_t on compress_hyper_12_13_chunk
+               Index Cond: (c_time = LOCALTIME(1))
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timestamp = LOCALTIMESTAMP;
+                                                         QUERY PLAN                                                         
+----------------------------------------------------------------------------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Index Scan using compress_hyper_12_13_chunk__compressed_hypertable_12_c_date_c_t on compress_hyper_12_13_chunk
+               Index Cond: (c_timestamp = LOCALTIMESTAMP)
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timestamp = LOCALTIMESTAMP(1);
+                                                         QUERY PLAN                                                         
+----------------------------------------------------------------------------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Index Scan using compress_hyper_12_13_chunk__compressed_hypertable_12_c_date_c_t on compress_hyper_12_13_chunk
+               Index Cond: (c_timestamp = LOCALTIMESTAMP(1))
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = USER;
+                        QUERY PLAN                         
+-----------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Seq Scan on compress_hyper_12_13_chunk
+               Filter: (c_name = USER)
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = CURRENT_USER;
+                        QUERY PLAN                         
+-----------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Seq Scan on compress_hyper_12_13_chunk
+               Filter: (c_name = CURRENT_USER)
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = SESSION_USER;
+                        QUERY PLAN                         
+-----------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Seq Scan on compress_hyper_12_13_chunk
+               Filter: (c_name = SESSION_USER)
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = CURRENT_CATALOG;
+                        QUERY PLAN                         
+-----------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Seq Scan on compress_hyper_12_13_chunk
+               Filter: (c_name = CURRENT_CATALOG)
+(5 rows)
+
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = CURRENT_SCHEMA;
+                        QUERY PLAN                         
+-----------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         ->  Seq Scan on compress_hyper_12_13_chunk
+               Filter: (c_name = CURRENT_SCHEMA)
+(5 rows)
+
+-- current_query() is not a sqlvaluefunction and volatile so should not be pushed down
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = current_query();
+                        QUERY PLAN                         
+-----------------------------------------------------------
+ Custom Scan (ChunkAppend) on svf_pushdown
+   Chunks excluded during startup: 0
+   ->  Custom Scan (DecompressChunk) on _hyper_11_12_chunk
+         Filter: (c_name = current_query())
+         ->  Seq Scan on compress_hyper_12_13_chunk
+(5 rows)
+
diff --git a/tsl/test/expected/decompress_vector_qual.out b/tsl/test/expected/decompress_vector_qual.out
@@ -569,6 +569,12 @@ select count(*) from vectorqual where ts > case when '2021-01-01'::timestamp < '
      0
 (1 row)
 
+select count(*) from vectorqual where ts < LOCALTIMESTAMP + '3 years'::interval;
+ count 
+-------
+     5
+(1 row)
+
 -- This filter is not vectorized because the 'timestamp > timestamptz'
 -- operator is stable, not immutable, because it uses the current session
 -- timezone. We could transform it to something like
@@ -664,3 +670,11 @@ select * from date_table where ts <  '2021-01-02';
  01-01-2021
 (1 row)
 
+select * from date_table where ts <  CURRENT_DATE;
+     ts     
+------------
+ 01-03-2021
+ 01-02-2021
+ 01-01-2021
+(3 rows)
+
diff --git a/tsl/test/sql/compression_qualpushdown.sql b/tsl/test/sql/compression_qualpushdown.sql
@@ -153,3 +153,31 @@ EXPLAIN (costs off) SELECT '1' FROM deleteme_with_bytea WHERE bdata::text = '123
 
 DROP table deleteme;
 DROP table deleteme_with_bytea;
+
+-- test sqlvaluefunction pushdown
+CREATE TABLE svf_pushdown(time timestamptz, c_date date, c_time time, c_timetz timetz, c_timestamp timestamptz, c_name text);
+SELECT table_name FROM create_hypertable('svf_pushdown', 'time');
+ALTER TABLE svf_pushdown SET (timescaledb.compress,timescaledb.compress_segmentby='c_date,c_time, c_timetz,c_timestamp,c_name');
+
+INSERT INTO svf_pushdown SELECT '2020-01-01';
+SELECT compress_chunk(show_chunks('svf_pushdown'));
+
+-- constraints should be pushed down into scan below decompresschunk in all cases
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_date = CURRENT_DATE;
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timetz = CURRENT_TIME;
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timetz = CURRENT_TIME(1);
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timestamp = CURRENT_TIMESTAMP;
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timestamp = CURRENT_TIMESTAMP(1);
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_time = LOCALTIME;
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_time = LOCALTIME(1);
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timestamp = LOCALTIMESTAMP;
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_timestamp = LOCALTIMESTAMP(1);
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = USER;
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = CURRENT_USER;
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = SESSION_USER;
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = CURRENT_CATALOG;
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = CURRENT_SCHEMA;
+
+-- current_query() is not a sqlvaluefunction and volatile so should not be pushed down
+EXPLAIN (costs off) SELECT * FROM svf_pushdown WHERE c_name = current_query();
+
diff --git a/tsl/test/sql/decompress_vector_qual.sql b/tsl/test/sql/decompress_vector_qual.sql
@@ -176,6 +176,7 @@ select count(*) from vectorqual where ts > '2021-01-01 00:00:00'::timestamptz::t
 select count(*) from vectorqual where ts > '2021-01-01 00:00:00'::timestamp - interval '1 day';
 -- Expression that evaluates to Null.
 select count(*) from vectorqual where ts > case when '2021-01-01'::timestamp < '2022-01-01'::timestamptz then null else '2021-01-01 00:00:00'::timestamp end;
+select count(*) from vectorqual where ts < LOCALTIMESTAMP + '3 years'::interval;
 
 -- This filter is not vectorized because the 'timestamp > timestamptz'
 -- operator is stable, not immutable, because it uses the current session
@@ -220,3 +221,5 @@ select * from date_table where ts >= '2021-01-02';
 select * from date_table where ts =  '2021-01-02';
 select * from date_table where ts <= '2021-01-02';
 select * from date_table where ts <  '2021-01-02';
+select * from date_table where ts <  CURRENT_DATE;
+
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Implements: #6440 Allow SQLValueFunction pushdown into compressed scan