dbms: added calculation of min/max [#CONV-8691].

dbms/include/DB/Client/Connection.h

@@ -152,7 +152,6 @@ private:
 	SharedPtr<Exception> receiveException();
 	Progress receiveProgress();
 	BlockStreamProfileInfo receiveProfileInfo();
-	Block receiveTotals();
 
 	void initBlockInput();
 };

dbms/include/DB/Core/Defines.h

@@ -32,4 +32,4 @@
 #define DBMS_MIN_REVISION_WITH_PROFILING_PACKET					32029
 #define DBMS_MIN_REVISION_WITH_HEADER_BLOCK						32881
 #define DBMS_MIN_REVISION_WITH_USER_PASSWORD					34482
-#define DBMS_MIN_REVISION_WITH_TOTALS							35265
+#define DBMS_MIN_REVISION_WITH_TOTALS_EXTREMES					35265

dbms/include/DB/Core/Protocol.h

@@ -63,6 +63,7 @@ namespace Protocol
 			EndOfStream = 5,	/// Все пакеты были переданы.
 			ProfileInfo = 6,	/// Пакет с профайлинговой информацией.
 			Totals = 7,			/// Блок данных с тотальными значениями, со сжатием или без.
+			Extremes = 8,		/// Блок данных с минимумами и максимумами, аналогично.
 		};
 
 		/** NOTE: Если бы в качестве типа агрумента функции был бы Enum, то сравнение packet >= 0 && packet < 7
@@ -71,8 +72,8 @@ namespace Protocol
 		  */
 		inline const char * toString(UInt64 packet)
 		{
-			static const char * data[] = { "Hello", "Data", "Exception", "Progress", "Pong", "EndOfStream", "ProfileInfo" };
+			static const char * data[] = { "Hello", "Data", "Exception", "Progress", "Pong", "EndOfStream", "ProfileInfo", "Totals", "Extremes" };
-			return packet >= 0 && packet < 7
+			return packet >= 0 && packet < 9
 				? data[packet]
 				: "Unknown packet";
 		}

dbms/include/DB/DataStreams/BlockOutputStreamFromRowOutputStream.h

@@ -20,6 +20,7 @@ public:
 	
 	void setRowsBeforeLimit(size_t rows_before_limit);
 	void setTotals(const Block & totals);
+	void setExtremes(const Block & extremes);
 
 private:
 	RowOutputStreamPtr row_output;

dbms/include/DB/DataStreams/IBlockOutputStream.h

@@ -36,6 +36,7 @@ public:
 	  */
 	virtual void setRowsBeforeLimit(size_t rows_before_limit) {}
 	virtual void setTotals(const Block & totals) {}
+	virtual void setExtremes(const Block & extremes) {}
 
 	virtual ~IBlockOutputStream() {}
 	

dbms/include/DB/DataStreams/IProfilingBlockInputStream.h

@@ -70,7 +70,7 @@ class IProfilingBlockInputStream : public IBlockInputStream
 {
 public:
 	IProfilingBlockInputStream(StoragePtr owned_storage_ = StoragePtr())
-		: IBlockInputStream(owned_storage_), is_cancelled(false), quota(NULL), quota_mode(QUOTA_READ), prev_elapsed(0) {}
+		: IBlockInputStream(owned_storage_), is_cancelled(false), enabled_extremes(false), quota(NULL), quota_mode(QUOTA_READ), prev_elapsed(0) {}
 	
 	Block read();
 
@@ -79,6 +79,8 @@ public:
 
 	/// Получить "тотальные" значения. Берёт их из себя или из первого дочернего источника, в котором они есть. Их может не быть.
 	const Block & getTotals() const;
+	/// То же самое для минимумов и максимумов.
+	const Block & getExtremes() const;
 
 
 	/** Установить колбэк прогресса выполнения.
@@ -150,15 +152,22 @@ public:
 		quota_mode = quota_mode_;
 	}
 
+	/// Включить рассчёт минимумов и максимумов по столбцам результата.
+	void enableExtremes() { enabled_extremes = true; }
+
 protected:
 	BlockStreamProfileInfo info;
 	volatile bool is_cancelled;
 	ProgressCallback progress_callback;
 
+	bool enabled_extremes;
+
 	/// Дополнительная информация, которая может образоваться в процессе работы.
 
 	/// Тотальные значения при агрегации.
 	Block totals;
+	/// Минимумы и максимумы. Первая строчка блока - минимумы, вторая - максимумы.
+	Block extremes;
 
 	/// Ограничения и квоты.
 	
@@ -170,6 +179,11 @@ protected:
 
 	/// Наследники должны реализовать эту функцию.
 	virtual Block readImpl() = 0;
+
+
+	void updateExtremes(Block & block);
+	bool checkLimits();
+	void checkQuota(Block & block);
 };
 
 }

dbms/include/DB/DataStreams/IRowOutputStream.h

@@ -36,6 +36,7 @@ public:
 	  */
 	virtual void setRowsBeforeLimit(size_t rows_before_limit) {}
 	virtual void setTotals(const Block & totals) {}
+	virtual void setExtremes(const Block & extremes) {}
 
 	virtual ~IRowOutputStream() {}
 };

dbms/include/DB/DataStreams/JSONCompactRowOutputStream.h

@@ -25,6 +25,7 @@ public:
 
 protected:
 	void writeTotals();
+	void writeExtremes();
 };
 
 }

dbms/include/DB/DataStreams/JSONRowOutputStream.h

@@ -32,15 +32,14 @@ public:
 		rows_before_limit = rows_before_limit_;
 	}
 
-	void setTotals(const Block & totals_)
+	void setTotals(const Block & totals_) { totals = totals_; }
-	{
+	void setExtremes(const Block & extremes_) { extremes = extremes_; }
-		totals = totals_;
-	}
 
 protected:
 	
 	void writeRowsBeforeLimitAtLeast();
 	virtual void writeTotals();
+	virtual void writeExtremes();
 	
 	typedef std::vector<NameAndTypePair> NamesAndTypesVector;
 	
@@ -51,6 +50,7 @@ protected:
 	size_t rows_before_limit;
 	NamesAndTypesVector fields;
 	Block totals;
+	Block extremes;
 };
 
 }

dbms/include/DB/DataStreams/RemoteBlockInputStream.h

@@ -123,6 +123,7 @@ public:
 				case Protocol::Server::Progress:
 				case Protocol::Server::ProfileInfo:
 				case Protocol::Server::Totals:
+				case Protocol::Server::Extremes:
 					break;
 
 				case Protocol::Server::EndOfStream:
@@ -186,6 +187,10 @@ protected:
 					totals = packet.block;
 					break;
 
+				case Protocol::Server::Extremes:
+					extremes = packet.block;
+					break;
+
 				default:
 					throw Exception("Unknown packet from server", ErrorCodes::UNKNOWN_PACKET_FROM_SERVER);
 			}

dbms/include/DB/Interpreters/Settings.h

@@ -37,9 +37,11 @@ struct Settings
 	/// Максимальное количество попыток соединения с репликами.
 	size_t connections_with_failover_max_tries;
 	/** Переписывать запросы SELECT из CollapsingMergeTree с агрегатными функциями
-	 * для автоматического учета поля Sign
+	  * для автоматического учета поля Sign
-	 */
+	  */
 	bool sign_rewrite;
+	/// Считать минимумы и максимумы столбцов результата. Они могут выводиться в JSON-форматах.
+	bool extremes;
 
 	/// Всевозможные ограничения на выполнение запроса.
 	Limits limits;
@@ -58,7 +60,7 @@ struct Settings
 		poll_interval(DBMS_DEFAULT_POLL_INTERVAL),
 		distributed_connections_pool_size(DBMS_DEFAULT_DISTRIBUTED_CONNECTIONS_POOL_SIZE),
 		connections_with_failover_max_tries(DBMS_CONNECTION_POOL_WITH_FAILOVER_DEFAULT_MAX_TRIES),
-		sign_rewrite(false)
+		sign_rewrite(false), extremes(false)
 	{
 	}
 

dbms/src/Client/Client.cpp

@@ -675,6 +675,10 @@ private:
 				onTotals(packet.block);
 				return true;
 
+			case Protocol::Server::Extremes:
+				onExtremes(packet.block);
+				return true;
+
 			case Protocol::Server::Exception:
 				onException(*packet.exception);
 				last_exception = packet.exception;
@@ -755,6 +759,11 @@ private:
 		block_std_out->setTotals(block);
 	}
 
+	void onExtremes(Block & block)
+	{
+		block_std_out->setExtremes(block);
+	}
+
 
 	void onProgress(const Progress & progress)
 	{

dbms/src/Client/Connection.cpp

@@ -289,7 +289,13 @@ Connection::Packet Connection::receivePacket()
 			return res;
 
 		case Protocol::Server::Totals:
-			res.block = receiveTotals();
+			/// Блок с тотальными значениями передаётся так же, как обычный блок данных. Разница только в идентификаторе пакета.
+			res.block = receiveData();
+			return res;
+
+		case Protocol::Server::Extremes:
+			/// Аналогично.
+			res.block = receiveData();
 			return res;
 
 		case Protocol::Server::EndOfStream:
@@ -364,10 +370,4 @@ BlockStreamProfileInfo Connection::receiveProfileInfo()
 }
 
 
-Block Connection::receiveTotals()
-{
-	/// Блок с тотальными значениями передаётся так же, как обычный блок данных. Разница только в идентификаторе пакета.
-	return receiveData();
-}
-
 }

dbms/src/DataStreams/BlockOutputStreamFromRowOutputStream.cpp

@@ -43,4 +43,9 @@ void BlockOutputStreamFromRowOutputStream::setTotals(const Block & totals)
 	row_output->setTotals(totals);
 }
 
+void BlockOutputStreamFromRowOutputStream::setExtremes(const Block & extremes)
+{
+	row_output->setExtremes(extremes);
+}
+
 }

dbms/src/DataStreams/IProfilingBlockInputStream.cpp

@@ -3,6 +3,7 @@
 /*#include <Poco/Mutex.h>
 #include <Poco/Ext/ThreadNumber.h>*/
 
+#include <DB/Columns/ColumnConst.h>
 #include <DB/DataStreams/IProfilingBlockInputStream.h>
 
 
@@ -174,7 +175,18 @@ Block IProfilingBlockInputStream::read()
 	}*/
 
 	if (res)
+	{
 		info.update(res);
+
+		if (enabled_extremes)
+			updateExtremes(res);
+
+		if (!checkLimits())
+			return Block();
+
+		if (quota != NULL)
+			checkQuota(res);
+	}
 	else
 	{
 		/** Если поток закончился, то ещё попросим всех детей прервать выполнение.
@@ -188,6 +200,63 @@ Block IProfilingBlockInputStream::read()
 
 	progress(res);
 
+	return res;
+}
+
+
+void IProfilingBlockInputStream::updateExtremes(Block & block)
+{
+	size_t columns = block.columns();
+
+	if (!extremes)
+	{
+		extremes = block.cloneEmpty();
+
+		for (size_t i = 0; i < columns; ++i)
+		{
+			Field min_value;
+			Field max_value;
+
+			block.getByPosition(i).column->getExtremes(min_value, max_value);
+
+			ColumnPtr & column = extremes.getByPosition(i).column;
+
+			if (column->isConst())
+				column = dynamic_cast<const IColumnConst &>(*column).convertToFullColumn();
+
+			column->insert(min_value);
+			column->insert(max_value);
+		}
+	}
+	else
+	{
+		for (size_t i = 0; i < columns; ++i)
+		{
+			ColumnPtr & column = extremes.getByPosition(i).column;
+			
+			Field min_value = (*column)[0];
+			Field max_value = (*column)[1];
+
+			Field cur_min_value;
+			Field cur_max_value;
+
+			block.getByPosition(i).column->getExtremes(cur_min_value, cur_max_value);
+
+			if (cur_min_value < min_value)
+				min_value = cur_min_value;
+			if (cur_max_value > max_value)
+				max_value = cur_max_value;
+
+			column = column->cloneEmpty();
+			column->insert(min_value);
+			column->insert(max_value);
+		}
+	}
+}
+
+
+bool IProfilingBlockInputStream::checkLimits()
+{
 	/// Проверка ограничений.
 	if ((limits.max_rows_to_read && info.rows > limits.max_rows_to_read)
 		|| (limits.max_bytes_to_read && info.bytes > limits.max_bytes_to_read))
@@ -198,7 +267,7 @@ Block IProfilingBlockInputStream::read()
 				ErrorCodes::TOO_MUCH_ROWS);
 
 		if (limits.read_overflow_mode == Limits::BREAK)
-			return Block();
+			return false;
 
 		throw Exception("Logical error: unknown overflow mode", ErrorCodes::LOGICAL_ERROR);
 	}
@@ -212,7 +281,7 @@ Block IProfilingBlockInputStream::read()
 			ErrorCodes::TIMEOUT_EXCEEDED);
 
 		if (limits.timeout_overflow_mode == Limits::BREAK)
-			return Block();
+			return false;
 
 		throw Exception("Logical error: unknown overflow mode", ErrorCodes::LOGICAL_ERROR);
 	}
@@ -226,31 +295,31 @@ Block IProfilingBlockInputStream::read()
 			ErrorCodes::TOO_SLOW);
 	}
 
-	/// Проверка квоты.
+	return true;
-	if (quota != NULL)
+}
+
+
+void IProfilingBlockInputStream::checkQuota(Block & block)
+{
+	time_t current_time = time(0);
+	double total_elapsed = info.total_stopwatch.elapsedSeconds();
+
+	switch (quota_mode)
 	{
-		time_t current_time = time(0);
+		case QUOTA_READ:
-		double total_elapsed = info.total_stopwatch.elapsedSeconds();
+			quota->checkAndAddReadRowsBytes(current_time, block.rows(), block.bytes());
+			break;
 
-		switch (quota_mode)
+		case QUOTA_RESULT:
-		{
+			quota->checkAndAddResultRowsBytes(current_time, block.rows(), block.bytes());
-			case QUOTA_READ:
+			quota->checkAndAddExecutionTime(current_time, Poco::Timespan((total_elapsed - prev_elapsed) * 1000000.0));
-				quota->checkAndAddReadRowsBytes(current_time, res.rows(), res.bytes());
+			break;
-				break;
 
-			case QUOTA_RESULT:
+		default:
-				quota->checkAndAddResultRowsBytes(current_time, res.rows(), res.bytes());
+			throw Exception("Logical error: unknown quota mode.", ErrorCodes::LOGICAL_ERROR);
-				quota->checkAndAddExecutionTime(current_time, Poco::Timespan((total_elapsed - prev_elapsed) * 1000000.0));
-				break;
-
-			default:
-				throw Exception("Logical error: unknown quota mode.", ErrorCodes::LOGICAL_ERROR);
-		}
-
-		prev_elapsed = total_elapsed;
 	}
-	
+
-	return res;
+	prev_elapsed = total_elapsed;
 }
 
 
@@ -306,5 +375,23 @@ const Block & IProfilingBlockInputStream::getTotals() const
 	return totals;
 }
 
+const Block & IProfilingBlockInputStream::getExtremes() const
+{
+	if (extremes)
+		return extremes;
+
+	for (BlockInputStreams::const_iterator it = children.begin(); it != children.end(); ++it)
+	{
+		if (const IProfilingBlockInputStream * child = dynamic_cast<const IProfilingBlockInputStream *>(&**it))
+		{
+			const Block & res = child->getExtremes();
+			if (res)
+				return res;
+		}
+	}
+
+	return extremes;
+}
+
 
 }

dbms/src/DataStreams/JSONCompactRowOutputStream.cpp

@@ -67,4 +67,42 @@ void JSONCompactRowOutputStream::writeTotals()
 }
 
 
+static void writeExtremesElement(const char * title, const Block & extremes, size_t row_num, WriteBuffer & ostr)
+{
+	writeCString("\t\t\"", ostr);
+	writeCString(title, ostr);
+	writeCString("\": [", ostr);
+
+	size_t extremes_columns = extremes.columns();
+	for (size_t i = 0; i < extremes_columns; ++i)
+	{
+		if (i != 0)
+			writeChar(',', ostr);
+
+		const ColumnWithNameAndType & column = extremes.getByPosition(i);
+		column.type->serializeTextJSON((*column.column)[row_num], ostr);
+	}
+
+	writeChar(']', ostr);
+}
+
+void JSONCompactRowOutputStream::writeExtremes()
+{
+	if (extremes)
+	{
+		writeCString(",\n", ostr);
+		writeChar('\n', ostr);
+		writeCString("\t\"extremes\":\n", ostr);
+		writeCString("\t{\n", ostr);
+
+		writeExtremesElement("min", extremes, 0, ostr);
+		writeCString(",\n", ostr);
+		writeExtremesElement("max", extremes, 1, ostr);
+
+		writeChar('\n', ostr);
+		writeCString("\t}", ostr);
+	}
+}
+
+
 }

dbms/src/DataStreams/JSONRowOutputStream.cpp

@@ -88,6 +88,7 @@ void JSONRowOutputStream::writeSuffix()
 	writeCString("\t]", ostr);
 
 	writeTotals();
+	writeExtremes();
 
 	writeCString(",\n\n", ostr);
 	writeCString("\t\"rows\": ", ostr);
@@ -138,4 +139,48 @@ void JSONRowOutputStream::writeTotals()
 	}
 }
 
+
+static void writeExtremesElement(const char * title, const Block & extremes, size_t row_num, WriteBuffer & ostr)
+{
+	writeCString("\t\t\"", ostr);
+	writeCString(title, ostr);
+	writeCString("\":\n", ostr);
+	writeCString("\t\t{\n", ostr);
+
+	size_t extremes_columns = extremes.columns();
+	for (size_t i = 0; i < extremes_columns; ++i)
+	{
+		const ColumnWithNameAndType & column = extremes.getByPosition(i);
+
+		if (i != 0)
+			writeCString(",\n", ostr);
+
+		writeCString("\t\t\t", ostr);
+		writeDoubleQuotedString(column.name, ostr);
+		writeCString(": ", ostr);
+		column.type->serializeTextJSON((*column.column)[row_num], ostr);
+	}
+
+	writeChar('\n', ostr);
+	writeCString("\t\t}", ostr);
+}
+
+void JSONRowOutputStream::writeExtremes()
+{
+	if (extremes)
+	{
+		writeCString(",\n", ostr);
+		writeChar('\n', ostr);
+		writeCString("\t\"extremes\":\n", ostr);
+		writeCString("\t{\n", ostr);
+
+		writeExtremesElement("min", extremes, 0, ostr);
+		writeCString(",\n", ostr);
+		writeExtremesElement("max", extremes, 1, ostr);
+
+		writeChar('\n', ostr);
+		writeCString("\t}", ostr);
+	}
+}
+
 }

dbms/src/DataStreams/copyData.cpp

@@ -22,6 +22,7 @@ void copyData(IBlockInputStream & from, IBlockOutputStream & to)
 			to.setRowsBeforeLimit(input->getInfo().getRowsBeforeLimit());
 
 		to.setTotals(input->getTotals());
+		to.setExtremes(input->getExtremes());
 	}
 
 	from.readSuffix();

dbms/src/Interpreters/InterpreterSelectQuery.cpp

@@ -278,6 +278,12 @@ BlockInputStreamPtr InterpreterSelectQuery::execute()
 			/// Сначала выполняем DISTINCT во всех источниках.
 			executeDistinct(streams, true);
 
+			/// На этой стадии можно считать минимумы и максимумы, если надо.
+			if (settings.extremes)
+				for (BlockInputStreams::iterator it = streams.begin(); it != streams.end(); ++it)
+					if (IProfilingBlockInputStream * stream = dynamic_cast<IProfilingBlockInputStream *>(&**it))
+						stream->enableExtremes();
+
 			/** Оптимизация - если источников несколько и есть LIMIT, то сначала применим предварительный LIMIT,
 			  * ограничивающий число записей в каждом до offset + limit.
 			  */

dbms/src/Interpreters/Settings.cpp

@@ -29,6 +29,7 @@ void Settings::set(const String & name, const Field & value)
 	else if (name == "distributed_connections_pool_size") distributed_connections_pool_size = safeGet<UInt64>(value);
 	else if (name == "connections_with_failover_max_tries") connections_with_failover_max_tries = safeGet<UInt64>(value);
 	else if (name == "sign_rewrite")		sign_rewrite 		= safeGet<UInt64>(value);
+	else if (name == "extremes")			extremes 			= safeGet<UInt64>(value);
 	else if (name == "profile") 			setProfile(get<const String &>(value));
 	else if (!limits.trySet(name, value))
 		throw Exception("Unknown setting " + name, ErrorCodes::UNKNOWN_SETTING);
@@ -49,7 +50,8 @@ void Settings::set(const String & name, ReadBuffer & buf)
 		|| name == "max_distributed_connections"
 		|| name == "distributed_connections_pool_size"
 		|| name == "connections_with_failover_max_tries"
-		|| name == "sign_rewrite")
+		|| name == "sign_rewrite"
+		|| name == "extremes")
 	{
 		UInt64 value = 0;
 		readVarUInt(value, buf);
@@ -80,7 +82,8 @@ void Settings::set(const String & name, const String & value)
 		|| name == "max_distributed_connections"
 		|| name == "distributed_connections_pool_size"
 		|| name == "connections_with_failover_max_tries"
-		|| name == "sign_rewrite")
+		|| name == "sign_rewrite"
+		|| name == "extremes")
 	{
 		set(name, parse<UInt64>(value));
 	}
@@ -137,7 +140,8 @@ void Settings::serialize(WriteBuffer & buf) const
 	writeStringBinary("max_distributed_connections", buf);			writeVarUInt(max_distributed_connections, buf);
 	writeStringBinary("distributed_connections_pool_size", buf);	writeVarUInt(distributed_connections_pool_size, buf);
 	writeStringBinary("connections_with_failover_max_tries", buf);	writeVarUInt(connections_with_failover_max_tries, buf);
-	writeStringBinary("sign_rewrite", buf);						writeVarUInt(sign_rewrite, buf);
+	writeStringBinary("sign_rewrite", buf);							writeVarUInt(sign_rewrite, buf);
+	writeStringBinary("extremes", buf);								writeVarUInt(extremes, buf);
 
 	limits.serialize(buf);
 

dbms/src/Server/TCPHandler.cpp

@@ -245,6 +245,7 @@ void TCPHandler::processOrdinaryQuery()
 			if (!block)
 			{
 				sendTotals();
+				sendExtremes();
 				sendProfileInfo();
 			}
 			
@@ -275,7 +276,7 @@ void TCPHandler::sendProfileInfo()
 
 void TCPHandler::sendTotals()
 {
-	if (client_revision < DBMS_MIN_REVISION_WITH_TOTALS)
+	if (client_revision < DBMS_MIN_REVISION_WITH_TOTALS_EXTREMES)
 		return;
 
 	if (const IProfilingBlockInputStream * input = dynamic_cast<const IProfilingBlockInputStream *>(&*state.io.in))
@@ -296,6 +297,29 @@ void TCPHandler::sendTotals()
 }
 
 
+void TCPHandler::sendExtremes()
+{
+	if (client_revision < DBMS_MIN_REVISION_WITH_TOTALS_EXTREMES)
+		return;
+
+	if (const IProfilingBlockInputStream * input = dynamic_cast<const IProfilingBlockInputStream *>(&*state.io.in))
+	{
+		const Block & extremes = input->getExtremes();
+
+		if (extremes)
+		{
+			initBlockOutput();
+
+			writeVarUInt(Protocol::Server::Extremes, *out);
+
+			state.block_out->write(extremes);
+			state.maybe_compressed_out->next();
+			out->next();
+		}
+	}
+}
+
+
 void TCPHandler::logProfileInfo(Stopwatch & watch, IBlockInputStream & in)
 {
 	/// Выведем информацию о том, сколько считано строк и байт.

dbms/src/Server/TCPHandler.h

@@ -122,6 +122,7 @@ private:
 	void sendEndOfStream();
 	void sendProfileInfo();
 	void sendTotals();
+	void sendExtremes();
 
 	/// Создаёт state.block_in/block_out для чтения/записи блоков, в зависимости от того, включено ли сжатие.
 	void initBlockInput();