ClickHouse/dbms/Interpreters/InterpreterExplainQuery.cpp
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

139 lines
4.1 KiB
C++

#include <Interpreters/InterpreterExplainQuery.h>
#include <DataStreams/BlockIO.h>
#include <DataStreams/OneBlockInputStream.h>
#include <DataTypes/DataTypeString.h>
#include <Interpreters/InDepthNodeVisitor.h>
#include <Interpreters/IdentifierSemantic.h>
#include <Interpreters/getTableExpressions.h>
#include <Interpreters/InterpreterSelectWithUnionQuery.h>
#include <Parsers/DumpASTNode.h>
#include <Parsers/ASTSubquery.h>
#include <Parsers/queryToString.h>
#include <Parsers/ASTIdentifier.h>
#include <Parsers/ASTExplainQuery.h>
#include <Parsers/ASTTablesInSelectQuery.h>
#include <Parsers/ASTSelectWithUnionQuery.h>
#include <Core/Field.h>
#include <Common/typeid_cast.h>
#include <Storages/StorageView.h>
#include <sstream>
namespace DB
{
namespace
{
struct ExplainAnalyzedSyntaxMatcher
{
struct Data
{
bool analyzed = false;
const Context & context;
};
static bool needChildVisit(ASTPtr &, ASTPtr &) { return true; }
static void visit(ASTPtr & ast, Data & data)
{
if (auto * select_query = ast->as<ASTSelectQuery>())
visit(*select_query, ast, data);
if (auto * union_select_query = ast->as<ASTSelectWithUnionQuery>())
visit(*union_select_query, ast, data);
}
static void visit(ASTSelectQuery & select_query, ASTPtr &, Data & data)
{
if (!select_query.tables())
return;
for (const auto & child : select_query.tables()->children)
{
auto * tables_element = child->as<ASTTablesInSelectQueryElement>();
if (tables_element && tables_element->table_expression)
visit(*tables_element->table_expression->as<ASTTableExpression>(), select_query, data);
}
}
static void visit(ASTSelectWithUnionQuery &, ASTPtr & node, Data & data)
{
if (!data.analyzed)
{
data.analyzed = true;
InterpreterSelectWithUnionQuery interpreter(
node, data.context, SelectQueryOptions(QueryProcessingStage::FetchColumns).analyze().modify());
}
}
static void visit(ASTTableExpression & expression, ASTSelectQuery & select_query, Data & data)
{
if (data.context.getSettingsRef().enable_optimize_predicate_expression && expression.database_and_table_name)
{
if (const auto * identifier = expression.database_and_table_name->as<ASTIdentifier>())
{
auto table_id = data.context.resolveStorageID(*identifier);
const auto & storage = DatabaseCatalog::instance().getTable(table_id);
if (auto * storage_view = dynamic_cast<StorageView *>(storage.get()))
storage_view->getRuntimeViewQuery(&select_query, data.context, true);
}
}
}
};
using ExplainAnalyzedSyntaxVisitor = InDepthNodeVisitor<ExplainAnalyzedSyntaxMatcher, true>;
}
BlockIO InterpreterExplainQuery::execute()
{
BlockIO res;
res.in = executeImpl();
return res;
}
Block InterpreterExplainQuery::getSampleBlock()
{
Block block;
ColumnWithTypeAndName col;
col.name = "explain";
col.type = std::make_shared<DataTypeString>();
col.column = col.type->createColumn();
block.insert(col);
return block;
}
BlockInputStreamPtr InterpreterExplainQuery::executeImpl()
{
const auto & ast = query->as<ASTExplainQuery &>();
Block sample_block = getSampleBlock();
MutableColumns res_columns = sample_block.cloneEmptyColumns();
std::stringstream ss;
if (ast.getKind() == ASTExplainQuery::ParsedAST)
{
dumpAST(ast, ss);
}
else if (ast.getKind() == ASTExplainQuery::AnalyzedSyntax)
{
ExplainAnalyzedSyntaxVisitor::Data data{.context = context};
ExplainAnalyzedSyntaxVisitor(data).visit(query);
ast.children.at(0)->format(IAST::FormatSettings(ss, false));
}
res_columns[0]->insert(ss.str());
return std::make_shared<OneBlockInputStream>(sample_block.cloneWithColumns(std::move(res_columns)));
}
}