diff --git a/dbms/tests/queries/0_stateless/00395_nullable.reference b/dbms/tests/queries/0_stateless/00395_nullable.reference
index 91772122ff8..4bb959404df 100644
--- a/dbms/tests/queries/0_stateless/00395_nullable.reference
+++ b/dbms/tests/queries/0_stateless/00395_nullable.reference
@@ -1,38 +1,47 @@
+----- NULL value -----
 \N
 \N
 \N
 \N
+----- MergeTree engine -----
 1	1	a	a	[1]	[1]	['a']	['a']	2000-01-01
 1	1	a	a	[1]	[1]	['a']	[NULL]	2000-01-01
 1	1	a	a	[1]	[NULL]	['a']	['a']	2000-01-01
 1	1	a	\N	[1]	[1]	['a']	['a']	2000-01-01
 1	\N	a	a	[1]	[1]	['a']	['a']	2000-01-01
+----- Memory engine -----
 1	1	a	a	[1]	[1]	['a']	['a']	2000-01-01
 1	1	a	a	[1]	[1]	['a']	[NULL]	2000-01-01
 1	1	a	a	[1]	[NULL]	['a']	['a']	2000-01-01
 1	1	a	\N	[1]	[1]	['a']	['a']	2000-01-01
 1	\N	a	a	[1]	[1]	['a']	['a']	2000-01-01
+----- TinyLog engine -----
 1	1	a	a	[1]	[1]	['a']	['a']	2000-01-01
 1	1	a	a	[1]	[1]	['a']	[NULL]	2000-01-01
 1	1	a	a	[1]	[NULL]	['a']	['a']	2000-01-01
 1	1	a	\N	[1]	[1]	['a']	['a']	2000-01-01
 1	\N	a	a	[1]	[1]	['a']	['a']	2000-01-01
+----- Log engine -----
 1	1	a	a	[1]	[1]	['a']	['a']	2000-01-01
 1	1	a	a	[1]	[1]	['a']	[NULL]	2000-01-01
 1	1	a	a	[1]	[NULL]	['a']	['a']	2000-01-01
 1	1	a	\N	[1]	[1]	['a']	['a']	2000-01-01
 1	\N	a	a	[1]	[1]	['a']	['a']	2000-01-01
+----- StripeLog engine -----
 1	1	a	a	[1]	[1]	['a']	['a']	2000-01-01
 1	1	a	a	[1]	[1]	['a']	[NULL]	2000-01-01
 1	1	a	a	[1]	[NULL]	['a']	['a']	2000-01-01
 1	1	a	\N	[1]	[1]	['a']	['a']	2000-01-01
 1	\N	a	a	[1]	[1]	['a']	['a']	2000-01-01
+----- Insert with expression -----
 [2]
+----- Insert. Source and target columns have same types up to nullability. -----
 2	7
 4	3
 5	1
 6	9
 8	2
+----- Apply functions and aggregate functions on columns that may contain null values -----
 2	7	9	14
 5	1	6	35
 9	\N	\N	63
@@ -41,12 +50,14 @@
 \N	\N	\N	\N
 58
 406
+----- isNull, isNotNull -----
 2	7	0	1
 5	1	0	1
 9	\N	0	0
 42	42	0	1
 \N	6	1	1
 \N	\N	1	0
+----- ifNull, nullIf -----
 2	7	2
 5	1	5
 9	\N	9
@@ -59,6 +70,7 @@
 42	42	\N
 \N	6	\N
 \N	\N	\N
+----- coalesce -----
 \N
 1
 1
@@ -76,16 +88,19 @@
 42	42	42
 \N	6	6
 \N	\N	99
+----- assumeNotNull -----
 2
 5
 9
 42
+----- IS NULL, IS NOT NULL -----
 2
 5
 9
 42
 \N
 \N
+----- multiIf -----
 \N
 2
 \N
@@ -100,6 +115,7 @@ A\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0
 1
 99
 99
+----- Array functions -----
 [NULL]
 [NULL,NULL,NULL]
 [NULL,2,3]
@@ -108,6 +124,8 @@ A\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0
 [NULL,'b','c']
 ['a',NULL,'c']
 ['a','b',NULL]
+----- arrayElement -----
+----- constant arrays -----
 1
 \N
 2
@@ -120,6 +138,7 @@ d
 \N
 2
 3
+----- variable arrays -----
 2
 \N
 2
@@ -170,6 +189,8 @@ bc
 def
 ghij
 \N
+----- has -----
+----- constant arrays -----
 1
 1
 1
@@ -197,6 +218,7 @@ ghij
 1
 1
 1
+----- variable arrays -----
 1
 0
 1
@@ -270,6 +292,7 @@ ghij
 0
 0
 1
+----- Aggregation -----
 A	0	2
 A	1	2
 B	1	4
diff --git a/dbms/tests/queries/0_stateless/00395_nullable.sql b/dbms/tests/queries/0_stateless/00395_nullable.sql
index 95283ddde90..66ac1766087 100644
--- a/dbms/tests/queries/0_stateless/00395_nullable.sql
+++ b/dbms/tests/queries/0_stateless/00395_nullable.sql
@@ -1,12 +1,12 @@
 
-/* NULL value */
+SELECT '----- NULL value -----';
 
 SELECT NULL;
 SELECT 1 + NULL;
 SELECT abs(NULL);
 SELECT NULL + NULL;
 
-/* MergeTree engine */
+SELECT '----- MergeTree engine -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(
@@ -24,7 +24,7 @@ INSERT INTO test.test1 VALUES (1, 1, 'a', 'a', [1], [1], ['a'], [NULL], '2000-01
 SELECT * FROM test.test1 ORDER BY col1,col2,col3,col4,col5,col6,col7,col8 ASC;
 
 
-/* Memory engine */
+SELECT '----- Memory engine -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(
@@ -41,7 +41,7 @@ INSERT INTO test.test1 VALUES (1, 1, 'a', 'a', [1], [NULL], ['a'], ['a'], '2000-
 INSERT INTO test.test1 VALUES (1, 1, 'a', 'a', [1], [1], ['a'], [NULL], '2000-01-01');
 SELECT * FROM test.test1 ORDER BY col1,col2,col3,col4,col5,col6,col7,col8 ASC;
 
-/* TinyLog engine */
+SELECT '----- TinyLog engine -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(
@@ -58,7 +58,7 @@ INSERT INTO test.test1 VALUES (1, 1, 'a', 'a', [1], [NULL], ['a'], ['a'], '2000-
 INSERT INTO test.test1 VALUES (1, 1, 'a', 'a', [1], [1], ['a'], [NULL], '2000-01-01');
 SELECT * FROM test.test1 ORDER BY col1,col2,col3,col4,col5,col6,col7,col8 ASC;
 
-/* Log engine */
+SELECT '----- Log engine -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(
@@ -75,7 +75,7 @@ INSERT INTO test.test1 VALUES (1, 1, 'a', 'a', [1], [NULL], ['a'], ['a'], '2000-
 INSERT INTO test.test1 VALUES (1, 1, 'a', 'a', [1], [1], ['a'], [NULL], '2000-01-01');
 SELECT * FROM test.test1 ORDER BY col1,col2,col3,col4,col5,col6,col7,col8 ASC;
 
-/* StripeLog engine */
+SELECT '----- StripeLog engine -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(
@@ -93,14 +93,14 @@ INSERT INTO test.test1 VALUES (1, 1, 'a', 'a', [1], [1], ['a'], [NULL], '2000-01
 SELECT * FROM test.test1 ORDER BY col1,col2,col3,col4,col5,col6,col7,col8 ASC;
 
 
-/* Insert with expression */
+SELECT '----- Insert with expression -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(col1 Array(Nullable(UInt64))) Engine=Memory;
 INSERT INTO test.test1(col1) VALUES ([1+1]);
 SELECT col1 FROM test.test1 ORDER BY col1 ASC;
 
-/* Insert. Source and target columns have same types up to nullability. */
+SELECT '----- Insert. Source and target columns have same types up to nullability. -----';
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(col1 Nullable(UInt64), col2 UInt64) Engine=Memory;
 DROP TABLE IF EXISTS test.test2;
@@ -109,7 +109,7 @@ INSERT INTO test.test1(col1,col2) VALUES (2,7)(6,9)(5,1)(4,3)(8,2);
 INSERT INTO test.test2(col1,col2) SELECT col1,col2 FROM test.test1;
 SELECT col1,col2 FROM test.test2 ORDER BY col1,col2 ASC;
 
-/* Apply functions and aggregate functions on columns that may contain null values */
+SELECT '----- Apply functions and aggregate functions on columns that may contain null values -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(col1 Nullable(UInt64), col2 Nullable(UInt64)) Engine=Memory;
@@ -118,16 +118,16 @@ SELECT col1, col2, col1 + col2, col1 * 7 FROM test.test1 ORDER BY col1,col2 ASC;
 SELECT sum(col1) FROM test.test1;
 SELECT sum(col1 * 7) FROM test.test1;
 
-/* isNull, isNotNull */
+SELECT '----- isNull, isNotNull -----';
 
 SELECT col1, col2, isNull(col1), isNotNull(col2) FROM test.test1 ORDER BY col1,col2 ASC;
 
-/* ifNull, nullIf */
+SELECT '----- ifNull, nullIf -----';
 
 SELECT col1, col2, ifNull(col1,col2) FROM test.test1 ORDER BY col1,col2 ASC;
 SELECT col1, col2, nullIf(col1,col2) FROM test.test1 ORDER BY col1,col2 ASC;
 
-/* coalesce */
+SELECT '----- coalesce -----';
 
 SELECT coalesce(NULL);
 SELECT coalesce(NULL, 1);
@@ -137,16 +137,16 @@ SELECT coalesce(NULL, NULL, NULL);
 SELECT col1, col2, coalesce(col1, col2) FROM test.test1 ORDER BY col1, col2 ASC;
 SELECT col1, col2, coalesce(col1, col2, 99) FROM test.test1 ORDER BY col1, col2 ASC;
 
-/* assumeNotNull */
+SELECT '----- assumeNotNull -----';
 
 SELECT res FROM (SELECT col1, assumeNotNull(col1) AS res FROM test.test1) WHERE col1 IS NOT NULL ORDER BY res ASC;
 
-/* IS NULL, IS NOT NULL */
+SELECT '----- IS NULL, IS NOT NULL -----';
 
 SELECT col1 FROM test.test1 WHERE col1 IS NOT NULL ORDER BY col1 ASC;
 SELECT col1 FROM test.test1 WHERE col1 IS NULL;
 
-/* multiIf */
+SELECT '----- multiIf -----';
 
 SELECT multiIf(1, NULL, 1, 3, 4);
 SELECT multiIf(1, 2, 1, NULL, 4);
@@ -168,7 +168,7 @@ CREATE TABLE test.test1(cond1 Nullable(UInt8), then1 Int8, cond2 UInt8, then2 Nu
 INSERT INTO test.test1(cond1,then1,cond2,then2,then3) VALUES(1,1,1,42,99)(0,7,1,99,42)(NULL,6,2,99,NULL);
 SELECT multiIf(cond1,then1,cond2,then2,then3) FROM test.test1;
 
-/* Array functions */
+SELECT '----- Array functions -----';
 
 SELECT [NULL];
 SELECT [NULL,NULL,NULL];
@@ -180,9 +180,9 @@ SELECT [NULL,'b','c'];
 SELECT ['a',NULL,'c'];
 SELECT ['a','b',NULL];
 
-/* arrayElement */
+SELECT '----- arrayElement -----';
 
-/* constant arrays */
+SELECT '----- constant arrays -----';
 
 SELECT arrayElement([1,NULL,2,3], 1);
 SELECT arrayElement([1,NULL,2,3], 2);
@@ -200,7 +200,7 @@ INSERT INTO test.test1(col1) VALUES(1),(2),(3),(4);
 
 SELECT arrayElement([1,NULL,2,3], col1) FROM test.test1;
 
-/* variable arrays */
+SELECT '----- variable arrays -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(col1 Array(Nullable(UInt64))) Engine=TinyLog;
@@ -248,9 +248,9 @@ INSERT INTO test.test1(col1,col2) VALUES([NULL,NULL,NULL,NULL],3);
 
 SELECT arrayElement(col1,col2) FROM test.test1;
 
-/* has */
+SELECT '----- has -----';
 
-/* constant arrays */
+SELECT '----- constant arrays -----';
 
 SELECT has([1,NULL,2,3], 1);
 SELECT has([1,NULL,2,3], NULL);
@@ -287,7 +287,7 @@ INSERT INTO test.test1(col1) VALUES('a'),('bc'),('def'),('ghij'),(NULL);
 
 SELECT has(['a',NULL,'def','ghij'], col1) FROM test.test1;
 
-/* variable arrays */
+SELECT '----- variable arrays -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(col1 Array(Nullable(UInt64))) Engine=TinyLog;
@@ -356,7 +356,7 @@ INSERT INTO test.test1(col1,col2) VALUES([NULL,NULL,NULL,NULL], NULL);
 
 SELECT has(col1,col2) FROM test.test1;
 
-/* Aggregation */
+SELECT '----- Aggregation -----';
 
 DROP TABLE IF EXISTS test.test1;
 CREATE TABLE test.test1(col1 Nullable(String), col2 Nullable(UInt8), col3 String) ENGINE=TinyLog;