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mirror of https://github.com/mariadb-corporation/mariadb-columnstore-engine.git synced 2025-04-21 19:45:56 +03:00
Sergey Zefirov b53c231ca6 MCOL-271 empty strings should not be NULLs (#2794)
This patch improves handling of NULLs in textual fields in ColumnStore.
Previously empty strings were considered NULLs and it could be a problem
if data scheme allows for empty strings. It was also one of major
reasons of behavior difference between ColumnStore and other engines in
MariaDB family.

Also, this patch fixes some other bugs and incorrect behavior, for
example, incorrect comparison for "column <= ''" which evaluates to
constant True for all purposes before this patch.
2023-03-30 21:18:29 +03:00

188 lines
4.6 KiB
C++

/* Copyright (C) 2014 InfiniDB, Inc.
Copyright (c) 2019 MariaDB Corporation
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: wf_min_max.cpp 3932 2013-06-25 16:08:10Z xlou $
//#define NDEBUG
#include <cassert>
#include <cmath>
#include <sstream>
#include <iomanip>
using namespace std;
#include <boost/shared_ptr.hpp>
using namespace boost;
#include "loggingid.h"
#include "errorcodes.h"
#include "idberrorinfo.h"
using namespace logging;
#include "rowgroup.h"
using namespace rowgroup;
#include "joblisttypes.h"
#include "calpontsystemcatalog.h"
using namespace execplan;
#include "windowfunctionstep.h"
using namespace joblist;
#include "wf_min_max.h"
namespace windowfunction
{
template <typename T>
boost::shared_ptr<WindowFunctionType> WF_min_max<T>::makeFunction(int id, const string& name, int ct,
WindowFunctionColumn* wc)
{
boost::shared_ptr<WindowFunctionType> func;
switch (ct)
{
case CalpontSystemCatalog::TINYINT:
case CalpontSystemCatalog::SMALLINT:
case CalpontSystemCatalog::MEDINT:
case CalpontSystemCatalog::INT:
case CalpontSystemCatalog::BIGINT:
{
func.reset(new WF_min_max<int64_t>(id, name));
break;
}
case CalpontSystemCatalog::UTINYINT:
case CalpontSystemCatalog::USMALLINT:
case CalpontSystemCatalog::UMEDINT:
case CalpontSystemCatalog::UINT:
case CalpontSystemCatalog::UBIGINT:
case CalpontSystemCatalog::DATE:
case CalpontSystemCatalog::DATETIME:
case CalpontSystemCatalog::TIMESTAMP:
case CalpontSystemCatalog::TIME:
{
func.reset(new WF_min_max<uint64_t>(id, name));
break;
}
case CalpontSystemCatalog::DECIMAL:
case CalpontSystemCatalog::UDECIMAL:
{
decltype(datatypes::MAXDECIMALWIDTH) width = wc->functionParms()[0]->resultType().colWidth;
if (width < datatypes::MAXDECIMALWIDTH)
{
if (ct == CalpontSystemCatalog::UDECIMAL)
func.reset(new WF_min_max<uint64_t>(id, name));
else
func.reset(new WF_min_max<int64_t>(id, name));
}
else
{
func.reset(new WF_min_max<int128_t>(id, name));
}
break;
}
case CalpontSystemCatalog::DOUBLE:
case CalpontSystemCatalog::UDOUBLE:
{
func.reset(new WF_min_max<double>(id, name));
break;
}
case CalpontSystemCatalog::FLOAT:
case CalpontSystemCatalog::UFLOAT:
{
func.reset(new WF_min_max<float>(id, name));
break;
}
case CalpontSystemCatalog::LONGDOUBLE:
{
func.reset(new WF_min_max<long double>(id, name));
break;
}
default:
{
func.reset(new WF_min_max<utils::NullString>(id, name));
break;
}
}
return func;
}
template <typename T>
WindowFunctionType* WF_min_max<T>::clone() const
{
return new WF_min_max<T>(*this);
}
template <typename T>
void WF_min_max<T>::resetData()
{
fCount = 0;
WindowFunctionType::resetData();
}
template <typename T>
void WF_min_max<T>::operator()(int64_t b, int64_t e, int64_t c)
{
// for unbounded - current row special handling
if (fPrev >= b && fPrev < c)
b = c;
else if (fPrev <= e && fPrev > c)
e = c;
uint64_t colIn = fFieldIndex[1];
for (int64_t i = b; i <= e; i++)
{
if (i % 1000 == 0 && fStep->cancelled())
break;
fRow.setData(getPointer(fRowData->at(i)));
if (fRow.isNullValue(colIn) == true)
continue;
T valIn;
getValue(colIn, valIn);
if ((fCount == 0) || (valIn < fValue && fFunctionId == WF__MIN) ||
(valIn > fValue && fFunctionId == WF__MAX))
{
fValue = valIn;
}
fCount++;
}
T* v = ((fCount > 0) ? &fValue : NULL);
setValue(fRow.getColType(fFieldIndex[0]), b, e, c, v);
fPrev = c;
}
template boost::shared_ptr<WindowFunctionType> WF_min_max<int64_t>::makeFunction(int, const string&, int,
WindowFunctionColumn*);
} // namespace windowfunction