dbms: development.

This commit is contained in:
Alexey Milovidov 2011-09-19 01:42:16 +00:00
parent c675a0fa40
commit 67d99d4773
18 changed files with 547 additions and 62 deletions

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@ -0,0 +1,58 @@
#pragma once
#include <DB/AggregateFunctions/IAggregateFunction.h>
#include <DB/Columns/ColumnVector.h>
namespace DB
{
/** Столбец, хранящий состояния агрегатных функций.
*/
class ColumnAggregateFunction : public ColumnVector<AggregateFunctionPtr>
{
public:
std::string getName() const { return "ColumnAggregateFunction"; }
bool isNumeric() const { return false; }
Field operator[](size_t n) const
{
return data[n];
}
void cut(size_t start, size_t length)
{
if (length == 0 || start + length > data.size())
throw Exception("Parameters start = "
+ Poco::NumberFormatter::format(start) + ", length = "
+ Poco::NumberFormatter::format(length) + " are out of bound in IColumnVector<T>::cut() method"
" (data.size() = " + Poco::NumberFormatter::format(data.size()) + ").",
ErrorCodes::PARAMETER_OUT_OF_BOUND);
if (start == 0)
data.resize(length);
else
{
Container_t tmp(data.begin() + start, data.begin() + start + length);
tmp.swap(data);
}
}
void insert(const Field & x)
{
data.push_back(boost::get<AggregateFunctionPtr>(x));
}
int compareAt(size_t n, size_t m, const IColumn & rhs_) const
{
return 0;
}
private:
Container_t data;
};
}

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@ -1,5 +1,4 @@
#ifndef DBMS_CORE_COLUMN_VECTOR_H
#define DBMS_CORE_COLUMN_VECTOR_H
#pragma once
#include <string.h>
@ -142,5 +141,3 @@ private:
}
#endif

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@ -68,6 +68,9 @@ namespace ErrorCodes
UNKNOWN_TABLE,
ONLY_FILTER_COLUMN_IN_BLOCK,
SYNTAX_ERROR,
UNKNOWN_AGGREGATE_FUNCTION,
CANNOT_READ_AGGREGATE_FUNCTION_FROM_TEXT,
CANNOT_WRITE_AGGREGATE_FUNCTION_AS_TEXT,
};
}

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@ -17,6 +17,10 @@
namespace DB
{
using Poco::SharedPtr;
class IAggregateFunction;
/** Типы данных для представления единичного значения произвольного типа в оперативке.
* Внимание! Предпочтительно вместо единичных значений хранить кусочки столбцов. См. Column.h
*/
@ -27,6 +31,7 @@ typedef boost::make_recursive_variant<
Int64,
Float64,
String,
SharedPtr<IAggregateFunction>,
std::vector<boost::recursive_variant_> /// Array, Tuple
>::type Field;
@ -43,6 +48,7 @@ namespace FieldType
Int64,
Float64,
String,
AggregateFunction,
Array
};
}
@ -65,6 +71,7 @@ public:
FieldType::Enum operator() (const Int64 & x) const { return FieldType::Int64; }
FieldType::Enum operator() (const Float64 & x) const { return FieldType::Float64; }
FieldType::Enum operator() (const String & x) const { return FieldType::String; }
FieldType::Enum operator() (const SharedPtr<IAggregateFunction> & x) const { return FieldType::AggregateFunction; }
FieldType::Enum operator() (const Array & x) const { return FieldType::Array; }
};
@ -72,19 +79,20 @@ public:
class FieldVisitorDump : public boost::static_visitor<std::string>
{
public:
std::string operator() (const Null & x) const { return "NULL"; }
std::string operator() (const UInt64 & x) const { return "UInt64_" + Poco::NumberFormatter::format(x); }
std::string operator() (const Int64 & x) const { return "Int64_" + Poco::NumberFormatter::format(x); }
std::string operator() (const Float64 & x) const { return "Float64_" + Poco::NumberFormatter::format(x); }
String operator() (const Null & x) const { return "NULL"; }
String operator() (const UInt64 & x) const { return "UInt64_" + Poco::NumberFormatter::format(x); }
String operator() (const Int64 & x) const { return "Int64_" + Poco::NumberFormatter::format(x); }
String operator() (const Float64 & x) const { return "Float64_" + Poco::NumberFormatter::format(x); }
String operator() (const SharedPtr<IAggregateFunction> & x) const { return "AggregateFunction"; }
std::string operator() (const String & x) const
String operator() (const String & x) const
{
std::stringstream s;
s << mysqlxx::quote << x;
return s.str();
}
std::string operator() (const Array & x) const
String operator() (const Array & x) const
{
std::stringstream s;
@ -109,6 +117,7 @@ public:
String operator() (const UInt64 & x) const { return Poco::NumberFormatter::format(x); }
String operator() (const Int64 & x) const { return Poco::NumberFormatter::format(x); }
String operator() (const Float64 & x) const { return Poco::NumberFormatter::format(x); }
String operator() (const SharedPtr<IAggregateFunction> & x) const { return "AggregateFunction"; }
String operator() (const String & x) const
{

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@ -1,5 +1,4 @@
#ifndef DBMS_CORE_ROW_H
#define DBMS_CORE_ROW_H
#pragma once
#include <vector>
@ -16,5 +15,3 @@ namespace DB
typedef std::vector<Field> Row;
}
#endif

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@ -1,5 +1,4 @@
#ifndef DBMS_DATA_STREAMS_IROWINPUTSTREAM_H
#define DBMS_DATA_STREAMS_IROWINPUTSTREAM_H
#pragma once
#include <DB/Core/Row.h>
@ -22,5 +21,3 @@ public:
};
}
#endif

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@ -0,0 +1,45 @@
#pragma once
#include <DB/AggregateFunctions/IAggregateFunction.h>
#include <DB/AggregateFunctions/AggregateFunctionFactory.h>
#include <DB/DataTypes/IDataType.h>
namespace DB
{
using Poco::SharedPtr;
/** Тип - состояние агрегатной функции.
*/
class DataTypeAggregateFunction : public IDataType
{
private:
const AggregateFunctionFactoryPtr factory;
public:
DataTypeAggregateFunction() : factory(new AggregateFunctionFactory) {}
DataTypeAggregateFunction(const AggregateFunctionFactoryPtr & factory_) : factory(factory_) {}
std::string getName() const { return "AggregateFunction"; }
DataTypePtr clone() const { return new DataTypeAggregateFunction(factory); }
void serializeBinary(const Field & field, WriteBuffer & ostr) const;
void deserializeBinary(Field & field, ReadBuffer & istr) const;
void serializeBinary(const IColumn & column, WriteBuffer & ostr) const;
void deserializeBinary(IColumn & column, ReadBuffer & istr, size_t limit) const;
void serializeText(const Field & field, WriteBuffer & ostr) const;
void deserializeText(Field & field, ReadBuffer & istr) const;
void serializeTextEscaped(const Field & field, WriteBuffer & ostr) const;
void deserializeTextEscaped(Field & field, ReadBuffer & istr) const;
void serializeTextQuoted(const Field & field, WriteBuffer & ostr, bool compatible = false) const;
void deserializeTextQuoted(Field & field, ReadBuffer & istr, bool compatible = false) const;
ColumnPtr createColumn() const;
ColumnPtr createConstColumn(size_t size, const Field & field) const;
};
}

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@ -8,6 +8,8 @@
namespace DB
{
using Poco::SharedPtr;
/** Позволяет создать тип данных по его имени.
*/
@ -15,7 +17,7 @@ class DataTypeFactory
{
public:
DataTypeFactory();
DataTypePtr get(const String & name);
DataTypePtr get(const String & name) const;
private:
typedef std::map<String, DataTypePtr> NonParametricDataTypes;
@ -24,5 +26,7 @@ private:
Poco::RegularExpression fixed_string_regexp;
};
typedef SharedPtr<DataTypeFactory> DataTypeFactoryPtr;
}

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@ -2,6 +2,7 @@
#include <DB/DataTypes/DataTypesNumberFixed.h>
#include <DB/DataTypes/DataTypeString.h>
#include <DB/DataTypes/DataTypeAggregateFunction.h>
namespace DB
@ -39,7 +40,12 @@ public:
DataTypePtr operator() (const String & x) const
{
return new DataTypeString;
return new DataTypeString;
}
DataTypePtr operator() (const AggregateFunctionPtr & x) const
{
return new DataTypeAggregateFunction;
}
DataTypePtr operator() (const Array & x) const

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@ -0,0 +1,38 @@
#pragma once
#include <DB/Core/ColumnNumbers.h>
#include <DB/DataStreams/IBlockInputStream.h>
#include <DB/AggregateFunctions/IAggregateFunction.h>
namespace DB
{
struct AggregateDescription
{
AggregateFunctionPtr function;
ColumnNumbers arguments;
};
typedef std::vector<AggregateDescription> AggregateDescriptions;
typedef std::map<Row, AggregateFunctions> AggregatedData;
/** Агрегирует поток блоков.
*/
class Aggregate
{
public:
Aggregate(const ColumnNumbers & keys_, AggregateDescriptions & aggregates_) : keys(keys_), aggregates(aggregates_) {};
AggregatedData execute(BlockInputStreamPtr stream);
private:
ColumnNumbers keys;
AggregateDescriptions aggregates;
};
}

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@ -9,6 +9,7 @@
#include <DB/Core/NamesAndTypes.h>
#include <DB/Storages/IStorage.h>
#include <DB/Functions/IFunction.h>
#include <DB/AggregateFunctions/AggregateFunctionFactory.h>
#include <DB/DataTypes/DataTypeFactory.h>
@ -31,12 +32,13 @@ typedef std::map<String, Tables> Databases;
*/
struct Context
{
String path; /// Путь к директории с данными, со слешем на конце.
SharedPtr<Databases> databases; /// Список БД и таблиц в них.
String current_database; /// Текущая БД.
SharedPtr<Functions> functions; /// Обычные функции.
SharedPtr<DataTypeFactory> data_type_factory; /// Типы данных.
NamesAndTypes columns; /// Столбцы текущей обрабатываемой таблицы.
String path; /// Путь к директории с данными, со слешем на конце.
SharedPtr<Databases> databases; /// Список БД и таблиц в них.
String current_database; /// Текущая БД.
SharedPtr<Functions> functions; /// Обычные функции.
AggregateFunctionFactoryPtr aggregate_function_factory; /// Агрегатные функции.
DataTypeFactoryPtr data_type_factory; /// Типы данных.
NamesAndTypes columns; /// Столбцы текущей обрабатываемой таблицы.
SharedPtr<Poco::FastMutex> mutex; /// Для доступа и модификации разделяемых объектов.

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@ -34,6 +34,8 @@ private:
PART_WHERE = 4,
PART_HAVING = 8,
PART_ORDER = 16,
PART_BELOW_AGGREGATE_FUNCTIONS = 32,
PART_ABOVE_AGGREGATE_FUNCTIONS = 64,
};

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@ -1,8 +1,8 @@
#ifndef DBMS_PARSERS_ASTFUNCTION_H
#define DBMS_PARSERS_ASTFUNCTION_H
#pragma once
#include <DB/Parsers/IAST.h>
#include <DB/Functions/IFunction.h>
#include <DB/AggregateFunctions/IAggregateFunction.h>
namespace DB
@ -20,6 +20,8 @@ public:
/// сама функция
FunctionPtr function;
/// или агрегатная функция
AggregateFunctionPtr aggregate_function;
/// типы возвращаемых значений
DataTypes return_types;
/// номера столбцов возвращаемых значений
@ -33,5 +35,3 @@ public:
};
}
#endif

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@ -0,0 +1,110 @@
#include <DB/IO/WriteHelpers.h>
#include <DB/IO/ReadHelpers.h>
#include <DB/Columns/ColumnConst.h>
#include <DB/Columns/ColumnAggregateFunction.h>
#include <DB/DataTypes/DataTypeAggregateFunction.h>
namespace DB
{
using Poco::SharedPtr;
void DataTypeAggregateFunction::serializeBinary(const Field & field, WriteBuffer & ostr) const
{
const AggregateFunctionPtr & value = boost::get<const AggregateFunctionPtr &>(field);
writeStringBinary(value->getName(), ostr);
value->serialize(ostr);
}
void DataTypeAggregateFunction::deserializeBinary(Field & field, ReadBuffer & istr) const
{
String name;
readStringBinary(name, istr);
AggregateFunctionPtr value = factory->get(name);
value->deserializeMerge(istr);
field = value;
}
void DataTypeAggregateFunction::serializeBinary(const IColumn & column, WriteBuffer & ostr) const
{
const ColumnAggregateFunction & real_column = dynamic_cast<const ColumnAggregateFunction &>(column);
const ColumnAggregateFunction::Container_t & vec = real_column.getData();
String name;
if (!vec.empty())
name = vec[0]->getName();
for (ColumnAggregateFunction::Container_t::const_iterator it = vec.begin(); it != vec.end(); ++it)
{
writeStringBinary(name, ostr);
(*it)->serialize(ostr);
}
}
void DataTypeAggregateFunction::deserializeBinary(IColumn & column, ReadBuffer & istr, size_t limit) const
{
ColumnAggregateFunction & real_column = dynamic_cast<ColumnAggregateFunction &>(column);
ColumnAggregateFunction::Container_t & vec = real_column.getData();
vec.reserve(limit);
for (size_t i = 0; i < limit; ++i)
{
if (istr.eof())
break;
String name;
readStringBinary(name, istr);
AggregateFunctionPtr value = factory->get(name);
value->deserializeMerge(istr);
vec.push_back(value);
}
}
void DataTypeAggregateFunction::serializeText(const Field & field, WriteBuffer & ostr) const
{
throw Exception("Cannot write aggregate function as text.", ErrorCodes::CANNOT_WRITE_AGGREGATE_FUNCTION_AS_TEXT);
}
void DataTypeAggregateFunction::deserializeText(Field & field, ReadBuffer & istr) const
{
throw Exception("Cannot read aggregate function from text.", ErrorCodes::CANNOT_READ_AGGREGATE_FUNCTION_FROM_TEXT);
}
void DataTypeAggregateFunction::serializeTextEscaped(const Field & field, WriteBuffer & ostr) const
{
throw Exception("Cannot write aggregate function as text.", ErrorCodes::CANNOT_WRITE_AGGREGATE_FUNCTION_AS_TEXT);
}
void DataTypeAggregateFunction::deserializeTextEscaped(Field & field, ReadBuffer & istr) const
{
throw Exception("Cannot read aggregate function from text.", ErrorCodes::CANNOT_READ_AGGREGATE_FUNCTION_FROM_TEXT);
}
void DataTypeAggregateFunction::serializeTextQuoted(const Field & field, WriteBuffer & ostr, bool compatible) const
{
throw Exception("Cannot write aggregate function as text.", ErrorCodes::CANNOT_WRITE_AGGREGATE_FUNCTION_AS_TEXT);
}
void DataTypeAggregateFunction::deserializeTextQuoted(Field & field, ReadBuffer & istr, bool compatible) const
{
throw Exception("Cannot read aggregate function from text.", ErrorCodes::CANNOT_READ_AGGREGATE_FUNCTION_FROM_TEXT);
}
ColumnPtr DataTypeAggregateFunction::createColumn() const
{
return new ColumnAggregateFunction;
}
ColumnPtr DataTypeAggregateFunction::createConstColumn(size_t size, const Field & field) const
{
return new ColumnConst<AggregateFunctionPtr>(size, boost::get<AggregateFunctionPtr>(field));
}
}

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@ -38,9 +38,9 @@ DataTypeFactory::DataTypeFactory()
}
DataTypePtr DataTypeFactory::get(const String & name)
DataTypePtr DataTypeFactory::get(const String & name) const
{
NonParametricDataTypes::iterator it = non_parametric_data_types.find(name);
NonParametricDataTypes::const_iterator it = non_parametric_data_types.find(name);
if (it != non_parametric_data_types.end())
return it->second;

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@ -0,0 +1,78 @@
#include <DB/Interpreters/Aggregate.h>
namespace DB
{
/** Простой алгоритм (агрегация с помощью std::map).
* Без оптимизации для агрегатных функций, принимающих не более одного значения.
* Без оптимизации по количеству ключей.
* Результат хранится в оперативке и должен полностью помещаться в оперативку.
*/
AggregatedData Aggregate::execute(BlockInputStreamPtr stream)
{
AggregatedData res;
size_t keys_size = keys.size();
size_t aggregates_size = aggregates.size();
Row key(keys_size);
Columns key_columns(keys_size);
typedef std::vector<Columns> AggregateColumns;
AggregateColumns aggregate_columns(aggregates_size);
typedef std::vector<Row> Rows;
Rows aggregate_arguments(aggregates_size);
for (size_t i = 0; i < aggregates_size; ++i)
{
aggregate_arguments[i].resize(aggregates[i].arguments.size());
aggregate_columns[i].resize(aggregates[i].arguments.size());
}
/// Читаем все данные
while (Block block = stream->read())
{
/// Запоминаем столбцы, с которыми будем работать
for (size_t i = 0, size = keys_size; i < size; ++i)
key_columns[i] = block.getByPosition(keys[i]).column;
for (size_t i = 0; i < aggregates_size; ++i)
for (size_t j = 0; j < aggregate_columns[i].size(); ++j)
aggregate_columns[i][j] = block.getByPosition(aggregates[i].arguments[j]).column;
size_t rows = block.rows();
/// Для всех строчек
for (size_t i = 0; i < rows; ++i)
{
/// Строим ключ
for (size_t j = 0; j < keys_size; ++j)
key[j] = (*key_columns[j])[i];
AggregatedData::iterator it = res.find(key);
if (it == res.end())
{
it = res.insert(std::make_pair(key, AggregateFunctions(aggregates_size))).first;
for (size_t j = 0; j < aggregates_size; ++j)
it->second[j] = aggregates[j].function->cloneEmpty();
}
/// Добавляем значения
for (size_t j = 0; j < aggregates_size; ++j)
{
for (size_t k = 0, size = aggregate_arguments[j].size(); k < size; ++k)
aggregate_arguments[j][k] = (*aggregate_columns[j][k])[i];
it->second[j]->add(aggregate_arguments[j]);
}
}
}
return res;
}
}

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@ -34,10 +34,11 @@ void Expression::addSemantic(ASTPtr & ast)
else if (ASTFunction * node = dynamic_cast<ASTFunction *>(&*ast))
{
Functions::const_iterator it = context.functions->find(node->name);
if (it == context.functions->end())
node->aggregate_function = context.aggregate_function_factory->tryGet(node->name);
if (it == context.functions->end() && node->aggregate_function.isNull())
throw Exception("Unknown function " + node->name, ErrorCodes::UNKNOWN_FUNCTION);
node->function = it->second;
if (it != context.functions->end())
node->function = it->second;
}
else if (ASTIdentifier * node = dynamic_cast<ASTIdentifier *>(&*ast))
{
@ -85,7 +86,10 @@ void Expression::checkTypes(ASTPtr ast)
}
/// Получаем типы результата
node->return_types = node->function->getReturnTypes(argument_types);
if (node->aggregate_function)
node->return_types.push_back(node->aggregate_function->getReturnType(argument_types));
else
node->return_types = node->function->getReturnTypes(argument_types);
}
}
@ -167,35 +171,38 @@ void Expression::executeImpl(ASTPtr ast, Block & block, unsigned part_id)
*/
if (ASTFunction * node = dynamic_cast<ASTFunction *>(&*ast))
{
/// Вставляем в блок столбцы - результаты вычисления функции
ColumnNumbers argument_numbers;
ColumnNumbers & result_numbers = node->return_column_numbers;
result_numbers.clear();
size_t res_num = 0;
for (DataTypes::const_iterator it = node->return_types.begin(); it != node->return_types.end(); ++it)
if (node->function)
{
ColumnWithNameAndType column;
column.type = *it;
column.name = node->getTreeID() + functionReturnValueSuffix(res_num);
/// Вставляем в блок столбцы - результаты вычисления функции
ColumnNumbers argument_numbers;
ColumnNumbers & result_numbers = node->return_column_numbers;
result_numbers.clear();
result_numbers.push_back(block.columns());
block.insert(column);
++res_num;
size_t res_num = 0;
for (DataTypes::const_iterator it = node->return_types.begin(); it != node->return_types.end(); ++it)
{
ColumnWithNameAndType column;
column.type = *it;
column.name = node->getTreeID() + functionReturnValueSuffix(res_num);
result_numbers.push_back(block.columns());
block.insert(column);
++res_num;
}
ASTs arguments = node->arguments->children;
for (ASTs::iterator it = arguments.begin(); it != arguments.end(); ++it)
{
if (ASTIdentifier * ident = dynamic_cast<ASTIdentifier *>(&**it))
argument_numbers.push_back(block.getPositionByName(ident->name));
else if (ASTFunction * func = dynamic_cast<ASTFunction *>(&**it))
argument_numbers.insert(argument_numbers.end(), func->return_column_numbers.begin(), func->return_column_numbers.end());
else
argument_numbers.push_back(block.getPositionByName((*it)->getTreeID()));
}
node->function->execute(block, argument_numbers, result_numbers);
}
ASTs arguments = node->arguments->children;
for (ASTs::iterator it = arguments.begin(); it != arguments.end(); ++it)
{
if (ASTIdentifier * ident = dynamic_cast<ASTIdentifier *>(&**it))
argument_numbers.push_back(block.getPositionByName(ident->name));
else if (ASTFunction * func = dynamic_cast<ASTFunction *>(&**it))
argument_numbers.insert(argument_numbers.end(), func->return_column_numbers.begin(), func->return_column_numbers.end());
else
argument_numbers.push_back(block.getPositionByName((*it)->getTreeID()));
}
node->function->execute(block, argument_numbers, result_numbers);
}
else if (ASTLiteral * node = dynamic_cast<ASTLiteral *>(&*ast))
{

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@ -0,0 +1,132 @@
#include <iostream>
#include <iomanip>
#include <Poco/Stopwatch.h>
#include <DB/DataTypes/DataTypesNumberFixed.h>
#include <DB/DataTypes/DataTypeString.h>
#include <DB/Columns/ColumnsNumber.h>
#include <DB/Columns/ColumnString.h>
#include <DB/DataStreams/IBlockInputStream.h>
#include <DB/Interpreters/Aggregate.h>
#include <DB/AggregateFunctions/AggregateFunctionFactory.h>
class OneBlockInputStream : public DB::IBlockInputStream
{
private:
const DB::Block & block;
bool has_been_read;
public:
OneBlockInputStream(const DB::Block & block_) : block(block_), has_been_read(false) {}
DB::Block read()
{
if (!has_been_read)
{
has_been_read = true;
return block;
}
else
return DB::Block();
}
DB::String getName() const { return "OneBlockInputStream"; }
};
int main(int argc, char ** argv)
{
try
{
size_t n = argc == 2 ? atoi(argv[1]) : 10;
DB::Block block;
DB::ColumnWithNameAndType column_x;
column_x.name = "x";
column_x.type = new DB::DataTypeInt16;
DB::ColumnInt16 * x = new DB::ColumnInt16;
column_x.column = x;
std::vector<Int16> & vec_x = x->getData();
vec_x.resize(n);
for (size_t i = 0; i < n; ++i)
vec_x[i] = i % 9;
block.insert(column_x);
const char * strings[] = {"abc", "def", "abcd", "defg", "ac"};
DB::ColumnWithNameAndType column_s1;
column_s1.name = "s1";
column_s1.type = new DB::DataTypeString;
column_s1.column = new DB::ColumnString;
for (size_t i = 0; i < n; ++i)
column_s1.column->insert(strings[i % 5]);
block.insert(column_s1);
DB::ColumnWithNameAndType column_s2;
column_s2.name = "s2";
column_s2.type = new DB::DataTypeString;
column_s2.column = new DB::ColumnString;
for (size_t i = 0; i < n; ++i)
column_s2.column->insert(strings[i % 3]);
block.insert(column_s2);
DB::BlockInputStreamPtr stream = new OneBlockInputStream(block);
DB::AggregatedData aggregated_data;
DB::ColumnNumbers key_column_numbers;
key_column_numbers.push_back(0);
key_column_numbers.push_back(1);
DB::AggregateFunctionFactory factory;
DB::AggregateDescriptions aggregate_descriptions(1);
aggregate_descriptions[0].function = factory.get("count");
DB::Aggregate aggregator(key_column_numbers, aggregate_descriptions);
{
Poco::Stopwatch stopwatch;
stopwatch.start();
aggregated_data = aggregator.execute(stream);
stopwatch.stop();
std::cout << std::fixed << std::setprecision(2)
<< "Elapsed " << stopwatch.elapsed() / 1000000.0 << " sec."
<< ", " << n * 1000000 / stopwatch.elapsed() << " rows/sec."
<< std::endl;
}
for (DB::AggregatedData::const_iterator it = aggregated_data.begin(); it != aggregated_data.end(); ++it)
{
for (DB::Row::const_iterator jt = it->first.begin(); jt != it->first.end(); ++jt)
std::cout << boost::apply_visitor(DB::FieldVisitorToString(), *jt) << '\t';
for (DB::AggregateFunctions::const_iterator jt = it->second.begin(); jt != it->second.end(); ++jt)
{
DB::Field result = (*jt)->getResult();
std::cout << boost::apply_visitor(DB::FieldVisitorToString(), result) << '\t';
}
std::cout << '\n';
}
}
catch (const DB::Exception & e)
{
std::cerr << e.message() << std::endl;
}
return 0;
}