mirror of
https://github.com/mariadb-corporation/mariadb-columnstore-engine.git
synced 2025-04-18 21:44:02 +03:00
63 lines
1.8 KiB
C++
63 lines
1.8 KiB
C++
/* Copyright (C) 2014 InfiniDB, Inc.
|
|
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License
|
|
as published by the Free Software Foundation; version 2 of
|
|
the License.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
|
|
MA 02110-1301, USA. */
|
|
|
|
// $Id: limitedorderby.h 9414 2013-04-22 22:18:30Z xlou $
|
|
|
|
/** @file */
|
|
|
|
#pragma once
|
|
|
|
#include <string>
|
|
#include "rowgroup.h"
|
|
#include "../../utils/windowfunction/idborderby.h"
|
|
|
|
namespace joblist
|
|
{
|
|
// forward reference
|
|
struct JobInfo;
|
|
|
|
// ORDER BY with LIMIT class
|
|
// This version is for subqueries, limit the result set to fit in memory,
|
|
// use ORDER BY to make the results consistent.
|
|
// The actual output are the first or last # of rows, which are NOT ordered.
|
|
class LimitedOrderBy : public ordering::IdbOrderBy
|
|
{
|
|
public:
|
|
LimitedOrderBy();
|
|
~LimitedOrderBy() override;
|
|
using ordering::IdbOrderBy::initialize;
|
|
void initialize(const rowgroup::RowGroup&, const JobInfo&, bool invertRules = false,
|
|
bool isMultiThreded = false);
|
|
void processRow(const rowgroup::Row&) override;
|
|
uint64_t getKeyLength() const override;
|
|
uint64_t getLimitCount() const
|
|
{
|
|
return fCount;
|
|
}
|
|
const std::string toString() const override;
|
|
|
|
void finalize();
|
|
|
|
protected:
|
|
uint64_t fStart;
|
|
uint64_t fCount;
|
|
uint64_t fUncommitedMemory;
|
|
static const uint64_t fMaxUncommited;
|
|
};
|
|
|
|
} // namespace joblist
|