Merge pull request #41336 from CurtizJ/dynamic-columns-21

Fix writing of empty columns of type `Object`

src/Columns/tests/gtest_column_object.cpp

@@ -1,8 +1,11 @@
 #include <Common/FieldVisitorsAccurateComparison.h>
 #include <DataTypes/getLeastSupertype.h>
+#include <DataTypes/ObjectUtils.h>
+#include <DataTypes/DataTypeTuple.h>
 #include <Interpreters/castColumn.h>
 #include <Interpreters/convertFieldToType.h>
 #include <Columns/ColumnObject.h>
+#include <Columns/ColumnTuple.h>
 #include <Common/FieldVisitorToString.h>
 
 #include <Common/randomSeed.h>
@@ -118,3 +121,36 @@ TEST(ColumnObject, InsertRangeFrom)
         checkFieldsAreEqual(subcolumn_dst, fields_dst);
     }
 }
+
+TEST(ColumnObject, Unflatten)
+{
+    auto check_empty_tuple = [](const auto & type, const auto & column)
+    {
+        const auto & type_tuple = assert_cast<const DataTypeTuple &>(*type);
+        const auto & column_tuple = assert_cast<const ColumnTuple &>(*column);
+
+        ASSERT_EQ(type_tuple.getElements().size(), 1);
+        ASSERT_EQ(type_tuple.getElements()[0]->getName(), "UInt8");
+        ASSERT_EQ(type_tuple.getElementNames()[0], ColumnObject::COLUMN_NAME_DUMMY);
+
+        ASSERT_EQ(column_tuple.getColumns().size(), 1);
+        ASSERT_EQ(column_tuple.getColumns()[0]->getName(), "UInt8");
+    };
+
+    {
+        auto column_object = ColumnObject::create(false);
+        auto [column, type] = unflattenObjectToTuple(*column_object);
+
+        check_empty_tuple(type, column);
+        ASSERT_EQ(column->size(), 0);
+    }
+
+    {
+        auto column_object = ColumnObject::create(false);
+        column_object->insertManyDefaults(5);
+        auto [column, type] = unflattenObjectToTuple(*column_object);
+
+        check_empty_tuple(type, column);
+        ASSERT_EQ(column->size(), 5);
+    }
+}

src/DataTypes/ObjectUtils.cpp

@@ -453,15 +453,19 @@ using SubcolumnsTreeWithColumns = SubcolumnsTree<ColumnWithTypeAndDimensions>;
 using Node = SubcolumnsTreeWithColumns::Node;
 
 /// Creates data type and column from tree of subcolumns.
-ColumnWithTypeAndDimensions createTypeFromNode(const Node * node)
+ColumnWithTypeAndDimensions createTypeFromNode(const Node & node)
 {
     auto collect_tuple_elemets = [](const auto & children)
     {
+        if (children.empty())
+            throw Exception(ErrorCodes::LOGICAL_ERROR, "Cannot create type from empty Tuple or Nested node");
+
         std::vector<std::tuple<String, ColumnWithTypeAndDimensions>> tuple_elements;
         tuple_elements.reserve(children.size());
         for (const auto & [name, child] : children)
         {
-            auto column = createTypeFromNode(child.get());
+            assert(child);
+            auto column = createTypeFromNode(*child);
             tuple_elements.emplace_back(name, std::move(column));
         }
 
@@ -475,13 +479,13 @@ ColumnWithTypeAndDimensions createTypeFromNode(const Node * node)
         return std::make_tuple(std::move(tuple_names), std::move(tuple_columns));
     };
 
-    if (node->kind == Node::SCALAR)
+    if (node.kind == Node::SCALAR)
     {
-        return node->data;
+        return node.data;
     }
-    else if (node->kind == Node::NESTED)
+    else if (node.kind == Node::NESTED)
     {
-        auto [tuple_names, tuple_columns] = collect_tuple_elemets(node->children);
+        auto [tuple_names, tuple_columns] = collect_tuple_elemets(node.children);
 
         Columns offsets_columns;
         offsets_columns.reserve(tuple_columns[0].array_dimensions + 1);
@@ -492,7 +496,7 @@ ColumnWithTypeAndDimensions createTypeFromNode(const Node * node)
         /// `k1 Array(Nested(k2 Int, k3 Int))` and k1 is marked as Nested
         /// and `k2` and `k3` has anonymous_array_level = 1 in that case.
 
-        const auto & current_array = assert_cast<const ColumnArray &>(*node->data.column);
+        const auto & current_array = assert_cast<const ColumnArray &>(*node.data.column);
         offsets_columns.push_back(current_array.getOffsetsPtr());
 
         auto first_column = tuple_columns[0].column;
@@ -529,7 +533,7 @@ ColumnWithTypeAndDimensions createTypeFromNode(const Node * node)
     }
     else
     {
-        auto [tuple_names, tuple_columns] = collect_tuple_elemets(node->children);
+        auto [tuple_names, tuple_columns] = collect_tuple_elemets(node.children);
 
         size_t num_elements = tuple_columns.size();
         Columns tuple_elements_columns(num_elements);
@@ -587,6 +591,15 @@ std::pair<ColumnPtr, DataTypePtr> unflattenObjectToTuple(const ColumnObject & co
 {
     const auto & subcolumns = column.getSubcolumns();
 
+    if (subcolumns.empty())
+    {
+        auto type = std::make_shared<DataTypeTuple>(
+            DataTypes{std::make_shared<DataTypeUInt8>()},
+            Names{ColumnObject::COLUMN_NAME_DUMMY});
+
+        return {type->createColumn()->cloneResized(column.size()), type};
+    }
+
     PathsInData paths;
     DataTypes types;
     Columns columns;
@@ -613,6 +626,9 @@ std::pair<ColumnPtr, DataTypePtr> unflattenTuple(
     assert(paths.size() == tuple_types.size());
     assert(paths.size() == tuple_columns.size());
 
+    if (paths.empty())
+        throw Exception(ErrorCodes::LOGICAL_ERROR, "Cannot unflatten empty Tuple");
+
     /// We add all paths to the subcolumn tree and then create a type from it.
     /// The tree stores column, type and number of array dimensions
     /// for each intermediate node.

src/DataTypes/Serializations/SubcolumnsTree.h

@@ -51,6 +51,8 @@ public:
     using NodeKind = typename Node::Kind;
     using NodePtr = std::shared_ptr<Node>;
 
+    SubcolumnsTree() : root(std::make_shared<Node>(Node::TUPLE)) {}
+
     /// Add a leaf without any data in other nodes.
     bool add(const PathInData & path, const NodeData & leaf_data)
     {
@@ -73,13 +75,9 @@ public:
     bool add(const PathInData & path, const NodeCreator & node_creator)
     {
         const auto & parts = path.getParts();
-
         if (parts.empty())
             return false;
 
-        if (!root)
-            root = std::make_shared<Node>(Node::TUPLE);
-
         Node * current_node = root.get();
         for (size_t i = 0; i < parts.size() - 1; ++i)
         {
@@ -166,13 +164,13 @@ public:
         return node;
     }
 
-    bool empty() const { return root == nullptr; }
+    bool empty() const { return root->children.empty(); }
     size_t size() const { return leaves.size(); }
 
     using Nodes = std::vector<NodePtr>;
 
     const Nodes & getLeaves() const { return leaves; }
-    const Node * getRoot() const { return root.get(); }
+    const Node & getRoot() const { return *root; }
 
     using iterator = typename Nodes::iterator;
     using const_iterator = typename Nodes::const_iterator;
@@ -186,11 +184,11 @@ public:
 private:
     const Node * findImpl(const PathInData & path, bool find_exact) const
     {
-        if (!root)
+        if (empty())
             return nullptr;
 
         const auto & parts = path.getParts();
-        const Node * current_node = root.get();
+        const auto * current_node = root.get();
 
         for (const auto & part : parts)
         {

src/Interpreters/AsynchronousInsertQueue.cpp

@@ -457,17 +457,20 @@ try
 
     format->addBuffer(std::move(last_buffer));
 
-    auto chunk = Chunk(executor.getResultColumns(), total_rows);
-    size_t total_bytes = chunk.bytes();
+    if (total_rows)
+    {
+        auto chunk = Chunk(executor.getResultColumns(), total_rows);
+        size_t total_bytes = chunk.bytes();
 
-    auto source = std::make_shared<SourceFromSingleChunk>(header, std::move(chunk));
-    pipeline.complete(Pipe(std::move(source)));
+        auto source = std::make_shared<SourceFromSingleChunk>(header, std::move(chunk));
+        pipeline.complete(Pipe(std::move(source)));
 
-    CompletedPipelineExecutor completed_executor(pipeline);
-    completed_executor.execute();
+        CompletedPipelineExecutor completed_executor(pipeline);
+        completed_executor.execute();
 
-    LOG_INFO(log, "Flushed {} rows, {} bytes for query '{}'",
-        total_rows, total_bytes, queryToString(key.query));
+        LOG_INFO(log, "Flushed {} rows, {} bytes for query '{}'",
+            total_rows, total_bytes, queryToString(key.query));
+    }
 
     for (const auto & entry : data->entries)
         if (!entry->isFinished())

tests/queries/0_stateless/02421_type_json_async_insert.reference

@@ -0,0 +1,5 @@
+Cannot parse object
+0
+0
+Cannot parse object
+aaa

tests/queries/0_stateless/02421_type_json_async_insert.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# Tags: no-fasttest
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CURDIR"/../shell_config.sh
+
+$CLICKHOUSE_CLIENT -q "DROP TABLE IF EXISTS t_json_async_insert"
+$CLICKHOUSE_CLIENT --allow_experimental_object_type=1 -q "CREATE TABLE t_json_async_insert (data JSON) ENGINE = MergeTree ORDER BY tuple()"
+
+$CLICKHOUSE_CLIENT --async_insert=1 --wait_for_async_insert=1 -q 'INSERT INTO t_json_async_insert FORMAT JSONAsObject {"aaa"}' 2>&1 | grep -o -m1 "Cannot parse object"
+$CLICKHOUSE_CLIENT -q "SELECT count() FROM t_json_async_insert"
+$CLICKHOUSE_CLIENT -q "SELECT count() FROM system.parts WHERE database = '$CLICKHOUSE_DATABASE' AND table = 't_json_async_insert'"
+
+$CLICKHOUSE_CLIENT --async_insert=1 --wait_for_async_insert=1 -q 'INSERT INTO t_json_async_insert FORMAT JSONAsObject {"aaa"}' 2>&1 | grep -o -m1 "Cannot parse object" &
+$CLICKHOUSE_CLIENT --async_insert=1 --wait_for_async_insert=1 -q 'INSERT INTO t_json_async_insert FORMAT JSONAsObject {"k1": "aaa"}' &
+
+wait
+
+$CLICKHOUSE_CLIENT -q "SELECT data.k1 FROM t_json_async_insert ORDER BY data.k1"
+$CLICKHOUSE_CLIENT -q "DROP TABLE IF EXISTS t_json_async_insert"

tests/queries/0_stateless/02421_type_json_empty_parts.reference

@@ -0,0 +1,26 @@
+Collapsing
+0
+0
+id	UInt64					
+s	Int8					
+data	Tuple(_dummy UInt8)					
+DELETE all
+2
+1
+id	UInt64					
+data	Tuple(k1 String, k2 String)					
+0
+0
+id	UInt64					
+data	Tuple(_dummy UInt8)					
+TTL
+1
+1
+id	UInt64					
+d	Date					
+data	Tuple(k1 String, k2 String)					
+0
+0
+id	UInt64					
+d	Date					
+data	Tuple(_dummy UInt8)					

tests/queries/0_stateless/02421_type_json_empty_parts.sql

@@ -0,0 +1,61 @@
+-- Tags: no-fasttest
+
+SET allow_experimental_object_type = 1;
+
+DROP TABLE IF EXISTS t_json_empty_parts;
+
+SELECT 'Collapsing';
+CREATE TABLE t_json_empty_parts (id UInt64, s Int8, data JSON) ENGINE = CollapsingMergeTree(s) ORDER BY id;
+
+INSERT INTO t_json_empty_parts VALUES (1, 1, '{"k1": "aaa"}') (1, -1, '{"k2": "bbb"}');
+
+SELECT count() FROM t_json_empty_parts;
+SELECT count() FROM system.parts WHERE table = 't_json_empty_parts' AND database = currentDatabase() AND active;
+DESC TABLE t_json_empty_parts SETTINGS describe_extend_object_types = 1;
+
+DROP TABLE t_json_empty_parts;
+
+DROP TABLE IF EXISTS t_json_empty_parts;
+
+SELECT 'DELETE all';
+CREATE TABLE t_json_empty_parts (id UInt64, data JSON) ENGINE = MergeTree ORDER BY id;
+
+INSERT INTO t_json_empty_parts VALUES (1, '{"k1": "aaa"}') (2, '{"k2": "bbb"}');
+
+SELECT count() FROM t_json_empty_parts;
+SELECT count() FROM system.parts WHERE table = 't_json_empty_parts' AND database = currentDatabase() AND active;
+DESC TABLE t_json_empty_parts SETTINGS describe_extend_object_types = 1;
+
+SET mutations_sync = 2;
+ALTER TABLE t_json_empty_parts DELETE WHERE 1;
+
+DETACH TABLE t_json_empty_parts;
+ATTACH TABLE t_json_empty_parts;
+
+SELECT count() FROM t_json_empty_parts;
+SELECT count() FROM system.parts WHERE table = 't_json_empty_parts' AND database = currentDatabase() AND active;
+DESC TABLE t_json_empty_parts SETTINGS describe_extend_object_types = 1;
+
+DROP TABLE IF EXISTS t_json_empty_parts;
+
+SELECT 'TTL';
+CREATE TABLE t_json_empty_parts (id UInt64, d Date, data JSON) ENGINE = MergeTree ORDER BY id TTL d WHERE id % 2 = 1;
+
+INSERT INTO t_json_empty_parts VALUES (1, '2000-01-01', '{"k1": "aaa"}') (2, '2000-01-01', '{"k2": "bbb"}');
+OPTIMIZE TABLE t_json_empty_parts FINAL;
+
+SELECT count() FROM t_json_empty_parts;
+SELECT count() FROM system.parts WHERE table = 't_json_empty_parts' AND database = currentDatabase() AND active;
+DESC TABLE t_json_empty_parts SETTINGS describe_extend_object_types = 1;
+
+ALTER TABLE t_json_empty_parts MODIFY TTL d;
+OPTIMIZE TABLE t_json_empty_parts FINAL;
+
+DETACH TABLE t_json_empty_parts;
+ATTACH TABLE t_json_empty_parts;
+
+SELECT count() FROM t_json_empty_parts;
+SELECT count() FROM system.parts WHERE table = 't_json_empty_parts' AND database = currentDatabase() AND active;
+DESC TABLE t_json_empty_parts SETTINGS describe_extend_object_types = 1;
+
+DROP TABLE IF EXISTS t_json_empty_parts;