ClickHouse/dbms/include/DB/Interpreters/QueryLog.h
2016-12-09 13:13:16 +03:00

70 lines
1.3 KiB
C++

#pragma once
#include <DB/Interpreters/SystemLog.h>
namespace DB
{
/** Allows to log information about queries execution:
* - info about start of query execution;
* - performance metrics (are set at the end of query execution);
* - info about errors of query execution.
*/
/// A struct which will be inserted as row into query_log table
struct QueryLogElement
{
enum Type
{
QUERY_START = 1,
QUERY_FINISH = 2,
EXCEPTION_BEFORE_START = 3,
EXCEPTION_WHILE_PROCESSING = 4,
};
Type type = QUERY_START;
/// Depending on the type of query and type of stage, not all the fields may be filled.
time_t event_time{};
time_t query_start_time{};
UInt64 query_duration_ms{};
/// The data fetched from DB to execute the query
UInt64 read_rows{};
UInt64 read_bytes{};
/// The data written to DB
UInt64 written_rows{};
UInt64 written_bytes{};
/// The data sent to the client
UInt64 result_rows{};
UInt64 result_bytes{};
UInt64 memory_usage{};
String query;
String exception;
String stack_trace;
ClientInfo client_info;
static std::string name() { return "QueryLog"; }
static Block createBlock();
void appendToBlock(Block & block) const;
};
/// Instead of typedef - to allow forward declaration.
class QueryLog : public SystemLog<QueryLogElement>
{
using SystemLog<QueryLogElement>::SystemLog;
};
}