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dbms: improved performance for very long arrays [#METR-17061].

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This commit is contained in:
Alexey Milovidov 2015-06-29 10:41:23 +03:00
parent 8c1d4358bc
commit d23de31335
4 changed files with 118 additions and 35 deletions
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126
dbms/include/DB/Columns/ColumnConst.h
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@ -24,36 +24,51 @@ public:
};
/** шаблон для столбцов-констант (столбцов одинаковых значений).
/** Столбец-константа может содержать внутри себя само значение,
* или, в случае массивов, SharedPtr от значения-массива,
* чтобы избежать проблем производительности при копировании очень больших массивов.
*
* T - тип значения,
* DataHolder - как значение хранится в таблице (либо T, либо SharedPtr<T>)
* Derived должен реализовать методы getDataFromHolderImpl - получить ссылку на значение из holder-а.
*
* Для строк и массивов реализации sizeOfField и byteSize могут быть некорректными.
*/
template <typename T>
class ColumnConst final : public IColumnConst
template <typename T, typename DataHolder, typename Derived>
class ColumnConstBase : public IColumnConst
{
protected:
size_t s;
DataHolder data;
DataTypePtr data_type;
T & getDataFromHolder() { return static_cast<Derived *>(this)->getDataFromHolderImpl(); }
const T & getDataFromHolder() const { return static_cast<const Derived *>(this)->getDataFromHolderImpl(); }
ColumnConstBase(size_t s_, const DataHolder & data_, DataTypePtr data_type_)
: s(s_), data(data_), data_type(data_type_) {}
public:
typedef T Type;
typedef typename NearestFieldType<T>::Type FieldType;
/// Для ColumnConst<Array> data_type_ должен быть ненулевым.
/// Для ColumnConst<String> data_type_ должен быть ненулевым, если тип данных FixedString.
ColumnConst(size_t s_, const T & data_, DataTypePtr data_type_ = DataTypePtr()) : s(s_), data(data_), data_type(data_type_) {}
std::string getName() const override { return "ColumnConst<" + TypeName<T>::get() + ">"; }
bool isNumeric() const override { return IsNumber<T>::value; }
bool isFixed() const override { return IsNumber<T>::value; }
size_t sizeOfField() const override { return sizeof(T); }
ColumnPtr cloneResized(size_t s_) const override { return new ColumnConst(s_, data, data_type); }
ColumnPtr cloneResized(size_t s_) const override { return new Derived(s_, data, data_type); }
size_t size() const override { return s; }
Field operator[](size_t n) const override { return FieldType(data); }
void get(size_t n, Field & res) const override { res = FieldType(data); }
Field operator[](size_t n) const override { return FieldType(getDataFromHolder()); }
void get(size_t n, Field & res) const override { res = FieldType(getDataFromHolder()); }
ColumnPtr cut(size_t start, size_t length) const override
{
return new ColumnConst(length, data, data_type);
return new Derived(length, data, data_type);
}
void insert(const Field & x) override
{
if (x.get<FieldType>() != FieldType(data))
if (x.get<FieldType>() != FieldType(getDataFromHolder()))
throw Exception("Cannot insert different element into constant column " + getName(),
ErrorCodes::CANNOT_INSERT_ELEMENT_INTO_CONSTANT_COLUMN);
++s;
@ -66,7 +81,7 @@ public:
void insertFrom(const IColumn & src, size_t n) override
{
if (data != static_cast<const ColumnConst<T> &>(src).data)
if (getDataFromHolder() != static_cast<const Derived &>(src).getDataFromHolder())
throw Exception("Cannot insert different element into constant column " + getName(),
ErrorCodes::CANNOT_INSERT_ELEMENT_INTO_CONSTANT_COLUMN);
++s;
@ -79,7 +94,7 @@ public:
if (s != filt.size())
throw Exception("Size of filter doesn't match size of column.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
return new ColumnConst(countBytesInFilter(filt), data, data_type);
return new Derived(countBytesInFilter(filt), data, data_type);
}
ColumnPtr replicate(const Offsets_t & offsets) const override
@ -88,7 +103,7 @@ public:
throw Exception("Size of offsets doesn't match size of column.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
size_t replicated_size = 0 == s ? 0 : offsets.back();
return new ColumnConst(replicated_size, data, data_type);
return new Derived(replicated_size, data, data_type);
}
size_t byteSize() const override { return sizeof(data) + sizeof(s); }
@ -103,13 +118,13 @@ public:
if (perm.size() < limit)
throw Exception("Size of permutation is less than required.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
return new ColumnConst(limit, data, data_type);
return new Derived(limit, data, data_type);
}
int compareAt(size_t n, size_t m, const IColumn & rhs_, int nan_direction_hint) const override
{
const ColumnConst<T> & rhs = static_cast<const ColumnConst<T> &>(rhs_);
return data < rhs.data /// TODO: правильное сравнение NaN-ов в константных столбцах.
const Derived & rhs = static_cast<const Derived &>(rhs_);
return getDataFromHolder() < rhs.getDataFromHolder() /// TODO: правильное сравнение NaN-ов в константных столбцах.
? -1
: (data == rhs.data
? 0
@ -123,30 +138,79 @@ public:
res[i] = i;
}
DataTypePtr & getDataType() { return data_type; }
const DataTypePtr & getDataType() const { return data_type; }
};
/** шаблон для столбцов-констант (столбцов одинаковых значений).
*/
template <typename T>
class ColumnConst final : public ColumnConstBase<T, T, ColumnConst<T>>
{
private:
friend class ColumnConstBase<T, T, ColumnConst<T>>;
T & getDataFromHolderImpl() { return this->data; }
const T & getDataFromHolderImpl() const { return this->data; }
public:
/// Для ColumnConst<Array> data_type_ должен быть ненулевым.
/// Для ColumnConst<String> data_type_ должен быть ненулевым, если тип данных FixedString.
ColumnConst(size_t s_, const T & data_, DataTypePtr data_type_ = DataTypePtr())
: ColumnConstBase<T, T, ColumnConst<T>>(s_, data_, data_type_) {}
StringRef getDataAt(size_t n) const override;
StringRef getDataAtWithTerminatingZero(size_t n) const override;
UInt64 get64(size_t n) const override;
/** Более эффективные методы манипуляции */
T & getData() { return data; }
const T & getData() const { return data; }
T & getData() { return this->data; }
const T & getData() const { return this->data; }
/** Преобразование из константы в полноценный столбец */
ColumnPtr convertToFullColumn() const override;
void getExtremes(Field & min, Field & max) const override
{
min = FieldType(data);
max = FieldType(data);
min = typename ColumnConstBase<T, T, ColumnConst<T>>::FieldType(this->data);
max = typename ColumnConstBase<T, T, ColumnConst<T>>::FieldType(this->data);
}
};
DataTypePtr & getDataType() { return data_type; }
const DataTypePtr & getDataType() const { return data_type; }
template <>
class ColumnConst<Array> final : public ColumnConstBase<Array, SharedPtr<Array>, ColumnConst<Array>>
{
private:
size_t s;
T data;
DataTypePtr data_type;
friend class ColumnConstBase<Array, SharedPtr<Array>, ColumnConst<Array>>;
Array & getDataFromHolderImpl() { return *data; }
const Array & getDataFromHolderImpl() const { return *data; }
public:
/// data_type_ должен быть ненулевым.
ColumnConst(size_t s_, const Array & data_, DataTypePtr data_type_ = DataTypePtr())
: ColumnConstBase<Array, SharedPtr<Array>, ColumnConst<Array>>(s_, new Array(data_), data_type_) {}
ColumnConst(size_t s_, const SharedPtr<Array> & data_, DataTypePtr data_type_ = DataTypePtr())
: ColumnConstBase<Array, SharedPtr<Array>, ColumnConst<Array>>(s_, data_, data_type_) {}
StringRef getDataAt(size_t n) const override;
StringRef getDataAtWithTerminatingZero(size_t n) const override;
UInt64 get64(size_t n) const override;
/** Более эффективные методы манипуляции */
const Array & getData() const { return *data; }
/** Преобразование из константы в полноценный столбец */
ColumnPtr convertToFullColumn() const override;
void getExtremes(Field & min, Field & max) const override
{
min = FieldType();
max = FieldType();
}
};
@ -158,19 +222,17 @@ template <typename T> ColumnPtr ColumnConst<T>::convertToFullColumn() const
{
ColumnVector<T> * res_ = new ColumnVector<T>;
ColumnPtr res = res_;
res_->getData().assign(s, data);
res_->getData().assign(this->s, this->data);
return res;
}
template <> ColumnPtr ColumnConst<String>::convertToFullColumn() const;
template <> ColumnPtr ColumnConst<Array>::convertToFullColumn() const;
template <typename T> StringRef ColumnConst<T>::getDataAt(size_t n) const
{
throw Exception("Method getDataAt is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED);
throw Exception("Method getDataAt is not supported for " + this->getName(), ErrorCodes::NOT_IMPLEMENTED);
}
template <> inline StringRef ColumnConst<String>::getDataAt(size_t n) const
@ -180,7 +242,7 @@ template <> inline StringRef ColumnConst<String>::getDataAt(size_t n) const
template <typename T> UInt64 ColumnConst<T>::get64(size_t n) const
{
throw Exception("Method get64 is not supported for " + getName(), ErrorCodes::NOT_IMPLEMENTED);
throw Exception("Method get64 is not supported for " + this->getName(), ErrorCodes::NOT_IMPLEMENTED);
}
/// Для элементарных типов.

23
dbms/src/Columns/ColumnConst.cpp
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@ -62,7 +62,7 @@ template <> ColumnPtr ColumnConst<String>::convertToFullColumn() const
}
template <> ColumnPtr ColumnConst<Array>::convertToFullColumn() const
ColumnPtr ColumnConst<Array>::convertToFullColumn() const
{
if (!data_type)
throw Exception("No data type specified for ColumnConstArray", ErrorCodes::LOGICAL_ERROR);
@ -71,7 +71,8 @@ template <> ColumnPtr ColumnConst<Array>::convertToFullColumn() const
if (!type)
throw Exception("Non-array data type specified for ColumnConstArray", ErrorCodes::LOGICAL_ERROR);
size_t array_size = data.size();
const Array & array = getDataFromHolderImpl();
size_t array_size = array.size();
ColumnPtr nested_column = type->getNestedType()->createColumn();
ColumnArray * res = new ColumnArray(nested_column);
@ -82,11 +83,27 @@ template <> ColumnPtr ColumnConst<Array>::convertToFullColumn() const
{
offsets[i] = (i + 1) * array_size;
for (size_t j = 0; j < array_size; ++j)
nested_column->insert(data[j]);
nested_column->insert(array[j]);
}
return res;
}
StringRef ColumnConst<Array>::getDataAt(size_t n) const
{
throw Exception("Method getDataAt is not supported for " + this->getName(), ErrorCodes::NOT_IMPLEMENTED);
}
UInt64 ColumnConst<Array>::get64(size_t n) const
{
throw Exception("Method get64 is not supported for " + this->getName(), ErrorCodes::NOT_IMPLEMENTED);
}
StringRef ColumnConst<Array>::getDataAtWithTerminatingZero(size_t n) const
{
throw Exception("Method getDataAt is not supported for " + this->getName(), ErrorCodes::NOT_IMPLEMENTED);
}
}

1
dbms/tests/queries/0_stateless/00186_very_long_arrays.reference Normal file
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@ -0,0 +1 @@
10000000

3
dbms/tests/queries/0_stateless/00186_very_long_arrays.sh Executable file
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@ -0,0 +1,3 @@
#!/bin/bash
(echo 'SELECT number FROM system.numbers WHERE transform(number, ['; seq 1 100000 | tr '\n' ','; echo '0],['; seq 1 100000 | tr '\n' ','; echo '0]) = 10000000 LIMIT 1';) | clickhouse-client --max_query_size=100000000