ClickHouse/src/Analyzer/UnionNode.cpp
2024-04-28 12:52:17 +03:00

281 lines
10 KiB
C++

#include <Analyzer/UnionNode.h>
#include <Common/SipHash.h>
#include <Common/FieldVisitorToString.h>
#include <IO/WriteBuffer.h>
#include <IO/WriteHelpers.h>
#include <IO/Operators.h>
#include <Parsers/ASTExpressionList.h>
#include <Parsers/ASTTablesInSelectQuery.h>
#include <Parsers/ASTWithElement.h>
#include <Parsers/ASTSubquery.h>
#include <Parsers/ASTSelectQuery.h>
#include <Parsers/ASTSelectWithUnionQuery.h>
#include <Parsers/ASTIdentifier.h>
#include <Parsers/ASTFunction.h>
#include <Core/ColumnWithTypeAndName.h>
#include <Core/NamesAndTypes.h>
#include <DataTypes/getLeastSupertype.h>
#include <Storages/IStorage.h>
#include <Interpreters/Context.h>
#include <Analyzer/QueryNode.h>
#include <Analyzer/Utils.h>
namespace DB
{
namespace ErrorCodes
{
extern const int TYPE_MISMATCH;
extern const int BAD_ARGUMENTS;
}
UnionNode::UnionNode(ContextMutablePtr context_, SelectUnionMode union_mode_)
: IQueryTreeNode(children_size)
, context(std::move(context_))
, union_mode(union_mode_)
{
if (union_mode == SelectUnionMode::UNION_DEFAULT ||
union_mode == SelectUnionMode::EXCEPT_DEFAULT ||
union_mode == SelectUnionMode::INTERSECT_DEFAULT)
throw Exception(ErrorCodes::BAD_ARGUMENTS, "UNION mode {} must be normalized", toString(union_mode));
children[queries_child_index] = std::make_shared<ListNode>();
}
NamesAndTypes UnionNode::computeProjectionColumns() const
{
if (recursive_cte_table)
return recursive_cte_table->columns;
std::vector<NamesAndTypes> projections;
NamesAndTypes query_node_projection;
const auto & query_nodes = getQueries().getNodes();
projections.reserve(query_nodes.size());
for (const auto & query_node : query_nodes)
{
if (auto * query_node_typed = query_node->as<QueryNode>())
query_node_projection = query_node_typed->getProjectionColumns();
else if (auto * union_node_typed = query_node->as<UnionNode>())
query_node_projection = union_node_typed->computeProjectionColumns();
projections.push_back(query_node_projection);
if (query_node_projection.size() != projections.front().size())
throw Exception(ErrorCodes::TYPE_MISMATCH, "UNION different number of columns in queries");
}
NamesAndTypes result_columns;
size_t projections_size = projections.size();
DataTypes projection_column_types;
projection_column_types.resize(projections_size);
size_t columns_size = query_node_projection.size();
for (size_t column_index = 0; column_index < columns_size; ++column_index)
{
for (size_t projection_index = 0; projection_index < projections_size; ++projection_index)
projection_column_types[projection_index] = projections[projection_index][column_index].type;
auto result_type = getLeastSupertype(projection_column_types);
result_columns.emplace_back(projections.front()[column_index].name, std::move(result_type));
}
return result_columns;
}
void UnionNode::removeUnusedProjectionColumns(const std::unordered_set<std::string> & used_projection_columns)
{
if (recursive_cte_table)
return;
auto projection_columns = computeProjectionColumns();
size_t projection_columns_size = projection_columns.size();
std::unordered_set<size_t> used_projection_column_indexes;
for (size_t i = 0; i < projection_columns_size; ++i)
{
const auto & projection_column = projection_columns[i];
if (used_projection_columns.contains(projection_column.name))
used_projection_column_indexes.insert(i);
}
auto & query_nodes = getQueries().getNodes();
for (auto & query_node : query_nodes)
{
if (auto * query_node_typed = query_node->as<QueryNode>())
query_node_typed->removeUnusedProjectionColumns(used_projection_column_indexes);
else if (auto * union_node_typed = query_node->as<UnionNode>())
union_node_typed->removeUnusedProjectionColumns(used_projection_column_indexes);
}
}
void UnionNode::removeUnusedProjectionColumns(const std::unordered_set<size_t> & used_projection_columns_indexes)
{
if (recursive_cte_table)
return;
auto & query_nodes = getQueries().getNodes();
for (auto & query_node : query_nodes)
{
if (auto * query_node_typed = query_node->as<QueryNode>())
query_node_typed->removeUnusedProjectionColumns(used_projection_columns_indexes);
else if (auto * union_node_typed = query_node->as<UnionNode>())
union_node_typed->removeUnusedProjectionColumns(used_projection_columns_indexes);
}
}
void UnionNode::dumpTreeImpl(WriteBuffer & buffer, FormatState & format_state, size_t indent) const
{
buffer << std::string(indent, ' ') << "UNION id: " << format_state.getNodeId(this);
if (hasAlias())
buffer << ", alias: " << getAlias();
if (is_subquery)
buffer << ", is_subquery: " << is_subquery;
if (is_cte)
buffer << ", is_cte: " << is_cte;
if (is_recursive_cte)
buffer << ", is_recursive_cte: " << is_recursive_cte;
if (recursive_cte_table)
buffer << ", recursive_cte_table: " << recursive_cte_table->storage->getStorageID().getNameForLogs();
if (!cte_name.empty())
buffer << ", cte_name: " << cte_name;
buffer << ", union_mode: " << toString(union_mode);
buffer << '\n' << std::string(indent + 2, ' ') << "QUERIES\n";
getQueriesNode()->dumpTreeImpl(buffer, format_state, indent + 4);
}
bool UnionNode::isEqualImpl(const IQueryTreeNode & rhs, CompareOptions) const
{
const auto & rhs_typed = assert_cast<const UnionNode &>(rhs);
if (recursive_cte_table && rhs_typed.recursive_cte_table &&
recursive_cte_table->getStorageID() != rhs_typed.recursive_cte_table->getStorageID())
return false;
else if ((recursive_cte_table && !rhs_typed.recursive_cte_table) || (!recursive_cte_table && rhs_typed.recursive_cte_table))
return false;
return is_subquery == rhs_typed.is_subquery && is_cte == rhs_typed.is_cte && is_recursive_cte == rhs_typed.is_recursive_cte
&& cte_name == rhs_typed.cte_name && union_mode == rhs_typed.union_mode;
}
void UnionNode::updateTreeHashImpl(HashState & state, CompareOptions) const
{
state.update(is_subquery);
state.update(is_cte);
state.update(is_recursive_cte);
if (recursive_cte_table)
{
auto full_name = recursive_cte_table->getStorageID().getFullNameNotQuoted();
state.update(full_name.size());
state.update(full_name);
}
state.update(cte_name.size());
state.update(cte_name);
state.update(static_cast<size_t>(union_mode));
}
QueryTreeNodePtr UnionNode::cloneImpl() const
{
auto result_union_node = std::make_shared<UnionNode>(context, union_mode);
result_union_node->is_subquery = is_subquery;
result_union_node->is_cte = is_cte;
result_union_node->is_recursive_cte = is_recursive_cte;
result_union_node->recursive_cte_table = recursive_cte_table;
result_union_node->cte_name = cte_name;
return result_union_node;
}
ASTPtr UnionNode::toASTImpl(const ConvertToASTOptions & options) const
{
auto select_with_union_query = std::make_shared<ASTSelectWithUnionQuery>();
select_with_union_query->union_mode = union_mode;
select_with_union_query->is_normalized = true;
select_with_union_query->children.push_back(getQueriesNode()->toAST(options));
select_with_union_query->list_of_selects = select_with_union_query->children.back();
ASTPtr result_query = std::move(select_with_union_query);
bool set_subquery_cte_name = true;
if (recursive_cte_table)
{
auto recursive_select_query = std::make_shared<ASTSelectQuery>();
recursive_select_query->recursive_with = true;
auto with_element_ast = std::make_shared<ASTWithElement>();
with_element_ast->name = cte_name;
with_element_ast->subquery = std::make_shared<ASTSubquery>(std::move(result_query));
with_element_ast->children.push_back(with_element_ast->subquery);
auto with_expression_list_ast = std::make_shared<ASTExpressionList>();
with_expression_list_ast->children.push_back(std::move(with_element_ast));
recursive_select_query->setExpression(ASTSelectQuery::Expression::WITH, std::move(with_expression_list_ast));
auto select_expression_list_ast = std::make_shared<ASTExpressionList>();
select_expression_list_ast->children.reserve(recursive_cte_table->columns.size());
for (const auto & recursive_cte_table_column : recursive_cte_table->columns)
select_expression_list_ast->children.push_back(std::make_shared<ASTIdentifier>(recursive_cte_table_column.name));
recursive_select_query->setExpression(ASTSelectQuery::Expression::SELECT, std::move(select_expression_list_ast));
auto table_expression_ast = std::make_shared<ASTTableExpression>();
table_expression_ast->children.push_back(std::make_shared<ASTTableIdentifier>(cte_name));
table_expression_ast->database_and_table_name = table_expression_ast->children.back();
auto tables_in_select_query_element_ast = std::make_shared<ASTTablesInSelectQueryElement>();
tables_in_select_query_element_ast->children.push_back(std::move(table_expression_ast));
tables_in_select_query_element_ast->table_expression = tables_in_select_query_element_ast->children.back();
ASTPtr tables_in_select_query_ast = std::make_shared<ASTTablesInSelectQuery>();
tables_in_select_query_ast->children.push_back(std::move(tables_in_select_query_element_ast));
recursive_select_query->setExpression(ASTSelectQuery::Expression::TABLES, std::move(tables_in_select_query_ast));
auto recursive_select_with_union_query = std::make_shared<ASTSelectWithUnionQuery>();
auto recursive_select_with_union_query_list_of_selects = std::make_shared<ASTExpressionList>();
recursive_select_with_union_query_list_of_selects->children.push_back(std::move(recursive_select_query));
recursive_select_with_union_query->children.push_back(std::move(recursive_select_with_union_query_list_of_selects));
recursive_select_with_union_query->list_of_selects = recursive_select_with_union_query->children.back();
result_query = std::move(recursive_select_with_union_query);
set_subquery_cte_name = false;
}
if (is_subquery)
{
auto subquery = std::make_shared<ASTSubquery>(std::move(result_query));
if (set_subquery_cte_name)
subquery->cte_name = cte_name;
result_query = std::move(subquery);
}
return result_query;
}
}