fix low card types in merge join (#12035)

src/Interpreters/MergeJoin.cpp

@@ -396,7 +396,6 @@ MergeJoin::MergeJoin(std::shared_ptr<TableJoin> table_join_, const Block & right
         if (required_right_keys.count(column.name))
             right_columns_to_add.insert(ColumnWithTypeAndName{nullptr, column.type, column.name});
 
-    JoinCommon::removeLowCardinalityInplace(right_columns_to_add);
     JoinCommon::createMissedColumns(right_columns_to_add);
 
     if (nullable_right_side)
@@ -513,7 +512,7 @@ bool MergeJoin::saveRightBlock(Block && block)
 bool MergeJoin::addJoinedBlock(const Block & src_block, bool)
 {
     Block block = materializeBlock(src_block);
-    JoinCommon::removeLowCardinalityInplace(block);
+    JoinCommon::removeLowCardinalityInplace(block, table_join->keyNamesRight());
 
     sortBlock(block, right_sort_description);
     return saveRightBlock(std::move(block));
@@ -525,7 +524,7 @@ void MergeJoin::joinBlock(Block & block, ExtraBlockPtr & not_processed)
     {
         JoinCommon::checkTypesOfKeys(block, table_join->keyNamesLeft(), right_table_keys, table_join->keyNamesRight());
         materializeBlockInplace(block);
-        JoinCommon::removeLowCardinalityInplace(block);
+        JoinCommon::removeLowCardinalityInplace(block, table_join->keyNamesLeft());
 
         sortBlock(block, left_sort_description);
     }

src/Interpreters/join_common.cpp

@@ -104,6 +104,16 @@ void removeLowCardinalityInplace(Block & block)
     }
 }
 
+void removeLowCardinalityInplace(Block & block, const Names & names)
+{
+    for (const String & column_name : names)
+    {
+        auto & col = block.getByName(column_name);
+        col.column = recursiveRemoveLowCardinality(col.column);
+        col.type = recursiveRemoveLowCardinality(col.type);
+    }
+}
+
 void splitAdditionalColumns(const Block & sample_block, const Names & key_names, Block & block_keys, Block & block_others)
 {
     block_others = materializeBlock(sample_block);

src/Interpreters/join_common.h

@@ -20,6 +20,7 @@ Columns materializeColumns(const Block & block, const Names & names);
 ColumnRawPtrs materializeColumnsInplace(Block & block, const Names & names);
 ColumnRawPtrs getRawPointers(const Columns & columns);
 void removeLowCardinalityInplace(Block & block);
+void removeLowCardinalityInplace(Block & block, const Names & names);
 
 /// Split key and other columns by keys name list
 void splitAdditionalColumns(const Block & sample_block, const Names & key_names, Block & block_keys, Block & block_others);

tests/queries/0_stateless/00800_low_cardinality_merge_join.reference

@@ -0,0 +1,41 @@
+0
+0
+0
+0
+0
+0
+0
+0
+0
+-
+0	0
+0	0
+0	0
+0	0
+0	0
+0	0
+0	0
+0	0
+0	0
+-
+0	1
+1	2
+2	0
+0	1
+1	2
+2	0
+0	1
+1	2
+2	0
+0	1
+1	2
+2	0
+0	1
+1	2
+2	0
+0	1
+1	2
+2	\N
+0	1
+1	2
+2	\N

tests/queries/0_stateless/00800_low_cardinality_merge_join.sql

@@ -0,0 +1,30 @@
+set join_algorithm = 'partial_merge';
+
+select * from (select dummy as val from system.one) s1 any left join (select dummy as val from system.one) s2 using val;
+select * from (select toLowCardinality(dummy) as val from system.one) s1 any left join (select dummy as val from system.one) s2 using val;
+select * from (select dummy as val from system.one) s1 any left join (select toLowCardinality(dummy) as val from system.one) s2 using val;
+select * from (select toLowCardinality(dummy) as val from system.one) s1 any left join (select toLowCardinality(dummy) as val from system.one) s2 using val;
+select * from (select toLowCardinality(toNullable(dummy)) as val from system.one) s1 any left join (select dummy as val from system.one) s2 using val;
+select * from (select dummy as val from system.one) s1 any left join (select toLowCardinality(toNullable(dummy)) as val from system.one) s2 using val;
+select * from (select toLowCardinality(toNullable(dummy)) as val from system.one) s1 any left join (select toLowCardinality(dummy) as val from system.one) s2 using val;
+select * from (select toLowCardinality(dummy) as val from system.one) s1 any left join (select toLowCardinality(toNullable(dummy)) as val from system.one) s2 using val;
+select * from (select toLowCardinality(toNullable(dummy)) as val from system.one) s1 any left join (select toLowCardinality(toNullable(dummy)) as val from system.one) s2 using val;
+select '-';
+select * from (select dummy as val from system.one) s1 any left join (select dummy as val from system.one) s2 on val + 0 = val * 1; -- { serverError 352 }
+select * from (select dummy as val from system.one) s1 any left join (select dummy as rval from system.one) s2 on val + 0 = rval * 1;
+select * from (select toLowCardinality(dummy) as val from system.one) s1 any left join (select dummy as rval from system.one) s2 on val + 0 = rval * 1;
+select * from (select dummy as val from system.one) s1 any left join (select toLowCardinality(dummy) as rval from system.one) s2 on val + 0 = rval * 1;
+select * from (select toLowCardinality(dummy) as val from system.one) s1 any left join (select toLowCardinality(dummy) as rval from system.one) s2 on val + 0 = rval * 1;
+select * from (select toLowCardinality(toNullable(dummy)) as val from system.one) s1 any left join (select dummy as rval from system.one) s2 on val + 0 = rval * 1;
+select * from (select dummy as val from system.one) s1 any left join (select toLowCardinality(toNullable(dummy)) as rval from system.one) s2 on val + 0 = rval * 1;
+select * from (select toLowCardinality(toNullable(dummy)) as val from system.one) s1 any left join (select toLowCardinality(dummy) as rval from system.one) s2 on val + 0 = rval * 1;
+select * from (select toLowCardinality(dummy) as val from system.one) s1 any left join (select toLowCardinality(toNullable(dummy)) as rval from system.one) s2 on val + 0 = rval * 1;
+select * from (select toLowCardinality(toNullable(dummy)) as val from system.one) s1 any left join (select toLowCardinality(toNullable(dummy)) as rval from system.one) s2 on val + 0 = rval * 1;
+select '-';
+select * from (select number as l from system.numbers limit 3) s1 any left join (select number as r from system.numbers limit 3) s2 on l + 1 = r * 1;
+select * from (select toLowCardinality(number) as l from system.numbers limit 3) s1 any left join (select number as r from system.numbers limit 3) s2 on l + 1 = r * 1;
+select * from (select number as l from system.numbers limit 3) s1 any left join (select toLowCardinality(number) as r from system.numbers limit 3) s2 on l + 1 = r * 1;
+select * from (select toLowCardinality(number) as l from system.numbers limit 3) s1 any left join (select toLowCardinality(number) as r from system.numbers limit 3) s2 on l + 1 = r * 1;
+select * from (select toLowCardinality(toNullable(number)) as l from system.numbers limit 3) s1 any left join (select toLowCardinality(number) as r from system.numbers limit 3) s2 on l + 1 = r * 1;
+select * from (select toLowCardinality(number) as l from system.numbers limit 3) s1 any left join (select toLowCardinality(toNullable(number)) as r from system.numbers limit 3) s2 on l + 1 = r * 1;
+select * from (select toLowCardinality(toNullable(number)) as l from system.numbers limit 3) s1 any left join (select toLowCardinality(toNullable(number)) as r from system.numbers limit 3) s2 on l + 1 = r * 1;

tests/queries/0_stateless/01353_low_cardinality_join_types.reference

@@ -0,0 +1,36 @@
+-
+LowCardinality(UInt64)	UInt64	String	LowCardinality(String)
+-
+UInt64	LowCardinality(UInt64)	LowCardinality(String)	String
+-
+LowCardinality(UInt64)	LowCardinality(UInt64)	LowCardinality(String)	LowCardinality(String)
+-
+LowCardinality(UInt64)	UInt64	String	LowCardinality(String)
+LowCardinality(UInt64)	UInt64	String	LowCardinality(String)
+LowCardinality(UInt64)	UInt64	String	LowCardinality(String)
+-
+UInt64	LowCardinality(UInt64)	LowCardinality(String)	String
+UInt64	LowCardinality(UInt64)	LowCardinality(String)	String
+UInt64	LowCardinality(UInt64)	LowCardinality(String)	String
+-
+LowCardinality(UInt64)	LowCardinality(UInt64)	LowCardinality(String)	LowCardinality(String)
+LowCardinality(UInt64)	LowCardinality(UInt64)	LowCardinality(String)	LowCardinality(String)
+LowCardinality(UInt64)	LowCardinality(UInt64)	LowCardinality(String)	LowCardinality(String)
+-
+LowCardinality(UInt64)	UInt64	String	LowCardinality(String)
+-
+UInt64	LowCardinality(UInt64)	LowCardinality(String)	String
+-
+LowCardinality(UInt64)	LowCardinality(UInt64)	LowCardinality(String)	LowCardinality(String)
+-
+LowCardinality(UInt64)	UInt64	String	LowCardinality(String)
+LowCardinality(UInt64)	UInt64	String	LowCardinality(String)
+LowCardinality(UInt64)	UInt64	String	LowCardinality(String)
+-
+UInt64	LowCardinality(UInt64)	LowCardinality(String)	String
+UInt64	LowCardinality(UInt64)	LowCardinality(String)	String
+UInt64	LowCardinality(UInt64)	LowCardinality(String)	String
+-
+LowCardinality(UInt64)	LowCardinality(UInt64)	LowCardinality(String)	LowCardinality(String)
+LowCardinality(UInt64)	LowCardinality(UInt64)	LowCardinality(String)	LowCardinality(String)
+LowCardinality(UInt64)	LowCardinality(UInt64)	LowCardinality(String)	LowCardinality(String)

tests/queries/0_stateless/01353_low_cardinality_join_types.sql

@@ -0,0 +1,75 @@
+set join_algorithm = 'hash';
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select toLowCardinality(number) k, toString(number) s from numbers(2)) as js1
+join (select number+1 k, toLowCardinality(toString(number+1)) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select number k, toLowCardinality(toString(number)) s from numbers(2)) as js1
+join (select toLowCardinality(number+1) k, toString(number+1) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select toLowCardinality(number) k, toLowCardinality(toString(number)) s from numbers(2)) as js1
+join (select toLowCardinality(number+1) k, toLowCardinality(toString(number+1)) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select toLowCardinality(number) k, toString(number) s from numbers(2)) as js1
+full join (select number+1 k, toLowCardinality(toString(number+1)) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select number k, toLowCardinality(toString(number)) s from numbers(2)) as js1
+full join (select toLowCardinality(number+1) k, toString(number+1) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select toLowCardinality(number) k, toLowCardinality(toString(number)) s from numbers(2)) as js1
+full join (select toLowCardinality(number+1) k, toLowCardinality(toString(number+1)) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+set join_algorithm = 'prefer_partial_merge';
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select toLowCardinality(number) k, toString(number) s from numbers(2)) as js1
+join (select number+1 k, toLowCardinality(toString(number+1)) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select number k, toLowCardinality(toString(number)) s from numbers(2)) as js1
+join (select toLowCardinality(number+1) k, toString(number+1) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select toLowCardinality(number) k, toLowCardinality(toString(number)) s from numbers(2)) as js1
+join (select toLowCardinality(number+1) k, toLowCardinality(toString(number+1)) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select toLowCardinality(number) k, toString(number) s from numbers(2)) as js1
+full join (select number+1 k, toLowCardinality(toString(number+1)) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select number k, toLowCardinality(toString(number)) s from numbers(2)) as js1
+full join (select toLowCardinality(number+1) k, toString(number+1) s from numbers(2)) as js2
+using k order by js1.k, js2.k;
+
+select '-';
+select toTypeName(materialize(js1.k)), toTypeName(materialize(js2.k)), toTypeName(materialize(js1.s)), toTypeName(materialize(js2.s))
+from (select toLowCardinality(number) k, toLowCardinality(toString(number)) s from numbers(2)) as js1
+full join (select toLowCardinality(number+1) k, toLowCardinality(toString(number+1)) s from numbers(2)) as js2
+using k order by js1.k, js2.k;