ClickHouse/src/Columns/ColumnNullable.cpp

851 lines
28 KiB
C++

#include <Common/Arena.h>
#include <Common/SipHash.h>
#include <Common/NaNUtils.h>
#include <Common/typeid_cast.h>
#include <Common/assert_cast.h>
#include <Common/WeakHash.h>
#include <Columns/ColumnNullable.h>
#include <Columns/ColumnConst.h>
#include <Columns/ColumnString.h>
#include <Columns/ColumnCompressed.h>
#include <Columns/ColumnLowCardinality.h>
#include <Processors/Transforms/ColumnGathererTransform.h>
#if USE_EMBEDDED_COMPILER
#include <DataTypes/Native.h>
#include <llvm/IR/IRBuilder.h>
#endif
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
extern const int ILLEGAL_COLUMN;
extern const int SIZES_OF_NESTED_COLUMNS_ARE_INCONSISTENT;
extern const int NOT_IMPLEMENTED;
}
ColumnNullable::ColumnNullable(MutableColumnPtr && nested_column_, MutableColumnPtr && null_map_)
: nested_column(std::move(nested_column_)), null_map(std::move(null_map_))
{
/// ColumnNullable cannot have constant nested column. But constant argument could be passed. Materialize it.
nested_column = getNestedColumn().convertToFullColumnIfConst();
if (!getNestedColumn().canBeInsideNullable())
throw Exception(ErrorCodes::ILLEGAL_COLUMN, "{} cannot be inside Nullable column", getNestedColumn().getName());
if (isColumnConst(*null_map))
throw Exception(ErrorCodes::ILLEGAL_COLUMN, "ColumnNullable cannot have constant null map");
}
StringRef ColumnNullable::getDataAt(size_t n) const
{
if (!isNullAt(n))
return getNestedColumn().getDataAt(n);
throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Method getDataAt is not supported for {} in case if value is NULL", getName());
}
void ColumnNullable::updateHashWithValue(size_t n, SipHash & hash) const
{
const auto & arr = getNullMapData();
hash.update(arr[n]);
if (arr[n] == 0)
getNestedColumn().updateHashWithValue(n, hash);
}
void ColumnNullable::updateWeakHash32(WeakHash32 & hash) const
{
auto s = size();
if (hash.getData().size() != s)
throw Exception(ErrorCodes::LOGICAL_ERROR, "Size of WeakHash32 does not match size of column: "
"column size is {}, hash size is {}", std::to_string(s), std::to_string(hash.getData().size()));
WeakHash32 old_hash = hash;
nested_column->updateWeakHash32(hash);
const auto & null_map_data = getNullMapData();
auto & hash_data = hash.getData();
auto & old_hash_data = old_hash.getData();
/// Use old data for nulls.
for (size_t row = 0; row < s; ++row)
if (null_map_data[row])
hash_data[row] = old_hash_data[row];
}
void ColumnNullable::updateHashFast(SipHash & hash) const
{
null_map->updateHashFast(hash);
nested_column->updateHashFast(hash);
}
MutableColumnPtr ColumnNullable::cloneResized(size_t new_size) const
{
MutableColumnPtr new_nested_col = getNestedColumn().cloneResized(new_size);
auto new_null_map = ColumnUInt8::create();
if (new_size > 0)
{
new_null_map->getData().resize(new_size);
size_t count = std::min(size(), new_size);
memcpy(new_null_map->getData().data(), getNullMapData().data(), count * sizeof(getNullMapData()[0]));
/// If resizing to bigger one, set all new values to NULLs.
if (new_size > count)
memset(&new_null_map->getData()[count], 1, new_size - count);
}
return ColumnNullable::create(std::move(new_nested_col), std::move(new_null_map));
}
Field ColumnNullable::operator[](size_t n) const
{
return isNullAt(n) ? Null() : getNestedColumn()[n];
}
void ColumnNullable::get(size_t n, Field & res) const
{
if (isNullAt(n))
res = Null();
else
getNestedColumn().get(n, res);
}
void ColumnNullable::insertData(const char * pos, size_t length)
{
if (pos == nullptr)
{
getNestedColumn().insertDefault();
getNullMapData().push_back(1);
}
else
{
getNestedColumn().insertData(pos, length);
getNullMapData().push_back(0);
}
}
StringRef ColumnNullable::serializeValueIntoArena(size_t n, Arena & arena, char const *& begin) const
{
const auto & arr = getNullMapData();
static constexpr auto s = sizeof(arr[0]);
auto * pos = arena.allocContinue(s, begin);
memcpy(pos, &arr[n], s);
if (arr[n])
return StringRef(pos, s);
auto nested_ref = getNestedColumn().serializeValueIntoArena(n, arena, begin);
/// serializeValueIntoArena may reallocate memory. Have to use ptr from nested_ref.data and move it back.
return StringRef(nested_ref.data - s, nested_ref.size + s);
}
const char * ColumnNullable::deserializeAndInsertFromArena(const char * pos)
{
UInt8 val = unalignedLoad<UInt8>(pos);
pos += sizeof(val);
getNullMapData().push_back(val);
if (val == 0)
pos = getNestedColumn().deserializeAndInsertFromArena(pos);
else
getNestedColumn().insertDefault();
return pos;
}
const char * ColumnNullable::skipSerializedInArena(const char * pos) const
{
UInt8 val = unalignedLoad<UInt8>(pos);
pos += sizeof(val);
if (val == 0)
return getNestedColumn().skipSerializedInArena(pos);
return pos;
}
void ColumnNullable::insertRangeFrom(const IColumn & src, size_t start, size_t length)
{
const ColumnNullable & nullable_col = assert_cast<const ColumnNullable &>(src);
getNullMapColumn().insertRangeFrom(*nullable_col.null_map, start, length);
getNestedColumn().insertRangeFrom(*nullable_col.nested_column, start, length);
}
void ColumnNullable::insert(const Field & x)
{
if (x.isNull())
{
getNestedColumn().insertDefault();
getNullMapData().push_back(1);
}
else
{
getNestedColumn().insert(x);
getNullMapData().push_back(0);
}
}
void ColumnNullable::insertFrom(const IColumn & src, size_t n)
{
const ColumnNullable & src_concrete = assert_cast<const ColumnNullable &>(src);
getNestedColumn().insertFrom(src_concrete.getNestedColumn(), n);
getNullMapData().push_back(src_concrete.getNullMapData()[n]);
}
void ColumnNullable::insertFromNotNullable(const IColumn & src, size_t n)
{
getNestedColumn().insertFrom(src, n);
getNullMapData().push_back(0);
}
void ColumnNullable::insertRangeFromNotNullable(const IColumn & src, size_t start, size_t length)
{
getNestedColumn().insertRangeFrom(src, start, length);
getNullMapData().resize_fill(getNullMapData().size() + length, 0);
}
void ColumnNullable::insertManyFromNotNullable(const IColumn & src, size_t position, size_t length)
{
for (size_t i = 0; i < length; ++i)
insertFromNotNullable(src, position);
}
void ColumnNullable::popBack(size_t n)
{
getNestedColumn().popBack(n);
getNullMapColumn().popBack(n);
}
ColumnPtr ColumnNullable::filter(const Filter & filt, ssize_t result_size_hint) const
{
ColumnPtr filtered_data = getNestedColumn().filter(filt, result_size_hint);
ColumnPtr filtered_null_map = getNullMapColumn().filter(filt, result_size_hint);
return ColumnNullable::create(filtered_data, filtered_null_map);
}
void ColumnNullable::expand(const IColumn::Filter & mask, bool inverted)
{
nested_column->expand(mask, inverted);
null_map->expand(mask, inverted);
}
ColumnPtr ColumnNullable::permute(const Permutation & perm, size_t limit) const
{
ColumnPtr permuted_data = getNestedColumn().permute(perm, limit);
ColumnPtr permuted_null_map = getNullMapColumn().permute(perm, limit);
return ColumnNullable::create(permuted_data, permuted_null_map);
}
ColumnPtr ColumnNullable::index(const IColumn & indexes, size_t limit) const
{
ColumnPtr indexed_data = getNestedColumn().index(indexes, limit);
ColumnPtr indexed_null_map = getNullMapColumn().index(indexes, limit);
return ColumnNullable::create(indexed_data, indexed_null_map);
}
#if USE_EMBEDDED_COMPILER
bool ColumnNullable::isComparatorCompilable() const
{
return nested_column->isComparatorCompilable();
}
llvm::Value * ColumnNullable::compileComparator(llvm::IRBuilderBase & builder, llvm::Value * lhs, llvm::Value * rhs,
llvm::Value * nan_direction_hint) const
{
llvm::IRBuilder<> & b = static_cast<llvm::IRBuilder<> &>(builder);
auto * head = b.GetInsertBlock();
llvm::Value * lhs_unwrapped_value = b.CreateExtractValue(lhs, {0});
llvm::Value * lhs_is_null_value = b.CreateExtractValue(lhs, {1});
llvm::Value * rhs_unwrapped_value = b.CreateExtractValue(rhs, {0});
llvm::Value * rhs_is_null_value = b.CreateExtractValue(rhs, {1});
llvm::Value * lhs_or_rhs_are_null = b.CreateOr(lhs_is_null_value, rhs_is_null_value);
auto * lhs_or_rhs_are_null_block = llvm::BasicBlock::Create(head->getContext(), "lhs_or_rhs_are_null_block", head->getParent());
auto * lhs_rhs_are_not_null_block = llvm::BasicBlock::Create(head->getContext(), "lhs_and_rhs_are_not_null_block", head->getParent());
auto * join_block = llvm::BasicBlock::Create(head->getContext(), "join_block", head->getParent());
b.CreateCondBr(lhs_or_rhs_are_null, lhs_or_rhs_are_null_block, lhs_rhs_are_not_null_block);
b.SetInsertPoint(lhs_or_rhs_are_null_block);
auto * lhs_equals_rhs_result = llvm::ConstantInt::getSigned(b.getInt8Ty(), 0);
llvm::Value * lhs_and_rhs_are_null = b.CreateAnd(lhs_is_null_value, rhs_is_null_value);
llvm::Value * lhs_is_null_result = b.CreateSelect(lhs_is_null_value, nan_direction_hint, b.CreateNeg(nan_direction_hint));
llvm::Value * lhs_or_rhs_are_null_block_result = b.CreateSelect(lhs_and_rhs_are_null, lhs_equals_rhs_result, lhs_is_null_result);
b.CreateBr(join_block);
b.SetInsertPoint(lhs_rhs_are_not_null_block);
llvm::Value * lhs_rhs_are_not_null_block_result
= nested_column->compileComparator(builder, lhs_unwrapped_value, rhs_unwrapped_value, nan_direction_hint);
b.CreateBr(join_block);
b.SetInsertPoint(join_block);
auto * result = b.CreatePHI(b.getInt8Ty(), 2);
result->addIncoming(lhs_or_rhs_are_null_block_result, lhs_or_rhs_are_null_block);
result->addIncoming(lhs_rhs_are_not_null_block_result, lhs_rhs_are_not_null_block);
return result;
}
#endif
int ColumnNullable::compareAtImpl(size_t n, size_t m, const IColumn & rhs_, int null_direction_hint, const Collator * collator) const
{
/// NULL values share the properties of NaN values.
/// Here the last parameter of compareAt is called null_direction_hint
/// instead of the usual nan_direction_hint and is used to implement
/// the ordering specified by either NULLS FIRST or NULLS LAST in the
/// ORDER BY construction.
const ColumnNullable & nullable_rhs = assert_cast<const ColumnNullable &>(rhs_);
bool lval_is_null = isNullAt(n);
bool rval_is_null = nullable_rhs.isNullAt(m);
if (unlikely(lval_is_null || rval_is_null))
{
if (lval_is_null && rval_is_null)
return 0;
else
return lval_is_null ? null_direction_hint : -null_direction_hint;
}
const IColumn & nested_rhs = nullable_rhs.getNestedColumn();
if (collator)
return getNestedColumn().compareAtWithCollation(n, m, nested_rhs, null_direction_hint, *collator);
return getNestedColumn().compareAt(n, m, nested_rhs, null_direction_hint);
}
int ColumnNullable::compareAt(size_t n, size_t m, const IColumn & rhs_, int null_direction_hint) const
{
return compareAtImpl(n, m, rhs_, null_direction_hint);
}
int ColumnNullable::compareAtWithCollation(size_t n, size_t m, const IColumn & rhs_, int null_direction_hint, const Collator & collator) const
{
return compareAtImpl(n, m, rhs_, null_direction_hint, &collator);
}
void ColumnNullable::compareColumn(const IColumn & rhs, size_t rhs_row_num,
PaddedPODArray<UInt64> * row_indexes, PaddedPODArray<Int8> & compare_results,
int direction, int nan_direction_hint) const
{
return doCompareColumn<ColumnNullable>(assert_cast<const ColumnNullable &>(rhs), rhs_row_num, row_indexes,
compare_results, direction, nan_direction_hint);
}
bool ColumnNullable::hasEqualValues() const
{
return hasEqualValuesImpl<ColumnNullable>();
}
void ColumnNullable::getPermutationImpl(IColumn::PermutationSortDirection direction, IColumn::PermutationSortStability stability,
size_t limit, int null_direction_hint, Permutation & res, const Collator * collator) const
{
/// Cannot pass limit because of unknown amount of NULLs.
if (collator)
getNestedColumn().getPermutationWithCollation(*collator, direction, stability, 0, null_direction_hint, res);
else
getNestedColumn().getPermutation(direction, stability, 0, null_direction_hint, res);
bool reverse = direction == IColumn::PermutationSortDirection::Descending;
const auto is_nulls_last = ((null_direction_hint > 0) != reverse);
size_t res_size = res.size();
if (!limit)
limit = res_size;
else
limit = std::min(res_size, limit);
/// For stable sort we must process all NULL values
if (unlikely(stability == IColumn::PermutationSortStability::Stable))
limit = res_size;
if (is_nulls_last)
{
/// Shift all NULL values to the end.
size_t read_idx = 0;
size_t write_idx = 0;
size_t end_idx = res_size;
while (read_idx < limit && !isNullAt(res[read_idx]))
{
++read_idx;
++write_idx;
}
++read_idx;
/// Invariants:
/// write_idx < read_idx
/// write_idx points to NULL
/// read_idx will be incremented to position of next not-NULL
/// there are range of NULLs between write_idx and read_idx - 1,
/// We are moving elements from end to begin of this range,
/// so range will "bubble" towards the end.
/// Relative order of NULL elements could be changed,
/// but relative order of non-NULLs is preserved.
while (read_idx < end_idx && write_idx < limit)
{
if (!isNullAt(res[read_idx]))
{
std::swap(res[read_idx], res[write_idx]);
++write_idx;
}
++read_idx;
}
if (unlikely(stability == IColumn::PermutationSortStability::Stable) && write_idx != res_size)
{
::sort(res.begin() + write_idx, res.begin() + res_size);
}
}
else
{
/// Shift all NULL values to the beginning.
ssize_t read_idx = res.size() - 1;
ssize_t write_idx = res.size() - 1;
while (read_idx >= 0 && !isNullAt(res[read_idx]))
{
--read_idx;
--write_idx;
}
--read_idx;
while (read_idx >= 0 && write_idx >= 0)
{
if (!isNullAt(res[read_idx]))
{
std::swap(res[read_idx], res[write_idx]);
--write_idx;
}
--read_idx;
}
if (unlikely(stability == IColumn::PermutationSortStability::Stable) && write_idx != 0)
{
::sort(res.begin(), res.begin() + write_idx + 1);
}
}
}
void ColumnNullable::updatePermutationImpl(IColumn::PermutationSortDirection direction, IColumn::PermutationSortStability stability,
size_t limit, int null_direction_hint, Permutation & res, EqualRanges & equal_ranges, const Collator * collator) const
{
if (equal_ranges.empty())
return;
/// We will sort nested columns into `new_ranges` and call updatePermutation in next columns with `null_ranges`.
EqualRanges new_ranges, null_ranges;
bool reverse = direction == IColumn::PermutationSortDirection::Descending;
const auto is_nulls_last = ((null_direction_hint > 0) != reverse);
if (is_nulls_last)
{
/// Shift all NULL values to the end.
for (const auto & [first, last] : equal_ranges)
{
/// Current interval is righter than limit.
if (limit && first > limit)
break;
/// Consider a half interval [first, last)
size_t read_idx = first;
size_t write_idx = first;
size_t end_idx = last;
/// We can't check the limit here because the interval is not sorted by nested column.
while (read_idx < end_idx && !isNullAt(res[read_idx]))
{
++read_idx;
++write_idx;
}
++read_idx;
/// Invariants:
/// write_idx < read_idx
/// write_idx points to NULL
/// read_idx will be incremented to position of next not-NULL
/// there are range of NULLs between write_idx and read_idx - 1,
/// We are moving elements from end to begin of this range,
/// so range will "bubble" towards the end.
/// Relative order of NULL elements could be changed,
/// but relative order of non-NULLs is preserved.
while (read_idx < end_idx && write_idx < end_idx)
{
if (!isNullAt(res[read_idx]))
{
std::swap(res[read_idx], res[write_idx]);
++write_idx;
}
++read_idx;
}
/// We have a range [first, write_idx) of non-NULL values
if (first != write_idx)
new_ranges.emplace_back(first, write_idx);
/// We have a range [write_idx, last) of NULL values
if (write_idx != last)
null_ranges.emplace_back(write_idx, last);
}
}
else
{
/// Shift all NULL values to the beginning.
for (const auto & [first, last] : equal_ranges)
{
/// Current interval is righter than limit.
if (limit && first > limit)
break;
ssize_t read_idx = last - 1;
ssize_t write_idx = last - 1;
ssize_t begin_idx = first;
while (read_idx >= begin_idx && !isNullAt(res[read_idx]))
{
--read_idx;
--write_idx;
}
--read_idx;
while (read_idx >= begin_idx && write_idx >= begin_idx)
{
if (!isNullAt(res[read_idx]))
{
std::swap(res[read_idx], res[write_idx]);
--write_idx;
}
--read_idx;
}
/// We have a range [write_idx+1, last) of non-NULL values
if (write_idx != static_cast<ssize_t>(last))
new_ranges.emplace_back(write_idx + 1, last);
/// We have a range [first, write_idx+1) of NULL values
if (static_cast<ssize_t>(first) != write_idx)
null_ranges.emplace_back(first, write_idx + 1);
}
}
if (collator)
getNestedColumn().updatePermutationWithCollation(*collator, direction, stability, limit, null_direction_hint, res, new_ranges);
else
getNestedColumn().updatePermutation(direction, stability, limit, null_direction_hint, res, new_ranges);
equal_ranges = std::move(new_ranges);
if (unlikely(stability == PermutationSortStability::Stable))
{
for (auto & null_range : null_ranges)
::sort(res.begin() + null_range.first, res.begin() + null_range.second);
}
std::move(null_ranges.begin(), null_ranges.end(), std::back_inserter(equal_ranges));
}
void ColumnNullable::getPermutation(IColumn::PermutationSortDirection direction, IColumn::PermutationSortStability stability,
size_t limit, int null_direction_hint, Permutation & res) const
{
getPermutationImpl(direction, stability, limit, null_direction_hint, res);
}
void ColumnNullable::updatePermutation(IColumn::PermutationSortDirection direction, IColumn::PermutationSortStability stability,
size_t limit, int null_direction_hint, IColumn::Permutation & res, EqualRanges & equal_ranges) const
{
updatePermutationImpl(direction, stability, limit, null_direction_hint, res, equal_ranges);
}
void ColumnNullable::getPermutationWithCollation(const Collator & collator, IColumn::PermutationSortDirection direction, IColumn::PermutationSortStability stability,
size_t limit, int null_direction_hint, Permutation & res) const
{
getPermutationImpl(direction, stability, limit, null_direction_hint, res, &collator);
}
void ColumnNullable::updatePermutationWithCollation(const Collator & collator, IColumn::PermutationSortDirection direction, IColumn::PermutationSortStability stability,
size_t limit, int null_direction_hint, Permutation & res, EqualRanges & equal_ranges) const
{
updatePermutationImpl(direction, stability, limit, null_direction_hint, res, equal_ranges, &collator);
}
void ColumnNullable::gather(ColumnGathererStream & gatherer)
{
gatherer.gather(*this);
}
void ColumnNullable::reserve(size_t n)
{
getNestedColumn().reserve(n);
getNullMapData().reserve(n);
}
void ColumnNullable::ensureOwnership()
{
getNestedColumn().ensureOwnership();
}
size_t ColumnNullable::byteSize() const
{
return getNestedColumn().byteSize() + getNullMapColumn().byteSize();
}
size_t ColumnNullable::byteSizeAt(size_t n) const
{
return sizeof(getNullMapData()[0]) + getNestedColumn().byteSizeAt(n);
}
size_t ColumnNullable::allocatedBytes() const
{
return getNestedColumn().allocatedBytes() + getNullMapColumn().allocatedBytes();
}
void ColumnNullable::protect()
{
getNestedColumn().protect();
getNullMapColumn().protect();
}
ColumnPtr ColumnNullable::compress() const
{
ColumnPtr nested_compressed = nested_column->compress();
ColumnPtr null_map_compressed = null_map->compress();
size_t byte_size = nested_column->byteSize() + null_map->byteSize();
return ColumnCompressed::create(size(), byte_size,
[nested_column = std::move(nested_compressed), null_map = std::move(null_map_compressed)]
{
return ColumnNullable::create(nested_column->decompress(), null_map->decompress());
});
}
namespace
{
/// The following function implements a slightly more general version
/// of getExtremes() than the implementation from Not-Null IColumns.
/// It takes into account the possible presence of nullable values.
void getExtremesWithNulls(const IColumn & nested_column, const NullMap & null_array, Field & min, Field & max, bool null_last = false)
{
size_t number_of_nulls = 0;
size_t n = null_array.size();
NullMap not_null_array(n);
for (auto i = 0ul; i < n; ++i)
{
if (null_array[i])
{
++number_of_nulls;
not_null_array[i] = 0;
}
else
{
not_null_array[i] = 1;
}
}
if (number_of_nulls == 0)
{
nested_column.getExtremes(min, max);
}
else if (number_of_nulls == n)
{
min = POSITIVE_INFINITY;
max = POSITIVE_INFINITY;
}
else
{
auto filtered_column = nested_column.filter(not_null_array, -1);
filtered_column->getExtremes(min, max);
if (null_last)
max = POSITIVE_INFINITY;
}
}
}
void ColumnNullable::getExtremes(Field & min, Field & max) const
{
getExtremesWithNulls(getNestedColumn(), getNullMapData(), min, max);
}
void ColumnNullable::getExtremesNullLast(Field & min, Field & max) const
{
getExtremesWithNulls(getNestedColumn(), getNullMapData(), min, max, true);
}
ColumnPtr ColumnNullable::replicate(const Offsets & offsets) const
{
ColumnPtr replicated_data = getNestedColumn().replicate(offsets);
ColumnPtr replicated_null_map = getNullMapColumn().replicate(offsets);
return ColumnNullable::create(replicated_data, replicated_null_map);
}
template <bool negative>
void ColumnNullable::applyNullMapImpl(const NullMap & map)
{
NullMap & arr = getNullMapData();
if (arr.size() != map.size())
throw Exception(ErrorCodes::LOGICAL_ERROR, "Inconsistent sizes of ColumnNullable objects");
for (size_t i = 0, size = arr.size(); i < size; ++i)
arr[i] |= negative ^ map[i];
}
void ColumnNullable::applyNullMap(const NullMap & map)
{
applyNullMapImpl<false>(map);
}
void ColumnNullable::applyNullMap(const ColumnUInt8 & map)
{
applyNullMapImpl<false>(map.getData());
}
void ColumnNullable::applyNegatedNullMap(const NullMap & map)
{
applyNullMapImpl<true>(map);
}
void ColumnNullable::applyNegatedNullMap(const ColumnUInt8 & map)
{
applyNullMapImpl<true>(map.getData());
}
void ColumnNullable::applyNullMap(const ColumnNullable & other)
{
applyNullMap(other.getNullMapColumn());
}
void ColumnNullable::checkConsistency() const
{
if (null_map->size() != getNestedColumn().size())
throw Exception(ErrorCodes::SIZES_OF_NESTED_COLUMNS_ARE_INCONSISTENT,
"Logical error: Sizes of nested column and null map of Nullable column are not equal");
}
ColumnPtr ColumnNullable::createWithOffsets(const IColumn::Offsets & offsets, const Field & default_field, size_t total_rows, size_t shift) const
{
ColumnPtr new_values;
ColumnPtr new_null_map;
if (default_field.getType() == Field::Types::Null)
{
auto default_column = nested_column->cloneEmpty();
default_column->insertDefault();
/// Value in main column, when null map is 1 is implementation defined. So, take any value.
new_values = nested_column->createWithOffsets(offsets, (*default_column)[0], total_rows, shift);
new_null_map = null_map->createWithOffsets(offsets, Field(1u), total_rows, shift);
}
else
{
new_values = nested_column->createWithOffsets(offsets, default_field, total_rows, shift);
new_null_map = null_map->createWithOffsets(offsets, Field(0u), total_rows, shift);
}
return ColumnNullable::create(new_values, new_null_map);
}
ColumnPtr ColumnNullable::getNestedColumnWithDefaultOnNull() const
{
auto res = nested_column->cloneEmpty();
const auto & null_map_data = getNullMapData();
size_t start = 0;
size_t end = null_map->size();
while (start < nested_column->size())
{
size_t next_null_index = start;
while (next_null_index < end && !null_map_data[next_null_index])
++next_null_index;
if (next_null_index != start)
res->insertRangeFrom(*nested_column, start, next_null_index - start);
if (next_null_index < end)
res->insertDefault();
start = next_null_index + 1;
}
return res;
}
ColumnPtr makeNullable(const ColumnPtr & column)
{
if (isColumnNullable(*column))
return column;
if (isColumnConst(*column))
return ColumnConst::create(makeNullable(assert_cast<const ColumnConst &>(*column).getDataColumnPtr()), column->size());
return ColumnNullable::create(column, ColumnUInt8::create(column->size(), 0));
}
ColumnPtr makeNullableOrLowCardinalityNullable(const ColumnPtr & column)
{
if (isColumnNullable(*column))
return column;
if (isColumnLowCardinalityNullable(*column))
return column;
if (isColumnConst(*column))
return ColumnConst::create(makeNullable(assert_cast<const ColumnConst &>(*column).getDataColumnPtr()), column->size());
if (column->lowCardinality())
return assert_cast<const ColumnLowCardinality &>(*column).cloneNullable();
return ColumnNullable::create(column, ColumnUInt8::create(column->size(), 0));
}
ColumnPtr makeNullableSafe(const ColumnPtr & column)
{
if (isColumnNullable(*column))
return column;
if (isColumnConst(*column))
return ColumnConst::create(makeNullableSafe(assert_cast<const ColumnConst &>(*column).getDataColumnPtr()), column->size());
if (column->canBeInsideNullable())
return makeNullable(column);
return column;
}
}