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DISTINCT in order: perf improvement

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+ reduce allocations in DistinctSortedChunkTransform
+ use it for final distinct as well
This commit is contained in:
Igor Nikonov 2022-07-20 20:44:47 +00:00
parent 3fb3015375
commit 965f96bd84
5 changed files with 49 additions and 45 deletions
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23
src/Processors/QueryPlan/DistinctStep.cpp
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@ -94,8 +94,10 @@ void DistinctStep::transformPipeline(QueryPipelineBuilder & pipeline, const Buil
SortDescription distinct_sort_desc = getSortDescription(input_stream.sort_description, columns);
if (!distinct_sort_desc.empty())
{
/// pre-distinct for sorted chunks
if (pre_distinct)
const bool sorted_stream = input_stream.sort_mode == DataStream::SortMode::Stream;
/// pre-distinct for sorted chunks or
/// final distinct for sorted stream (sorting inside and among chunks)
if (pre_distinct || sorted_stream)
{
pipeline.addSimpleTransform(
[&](const Block & header, QueryPipelineBuilder::StreamType stream_type) -> ProcessorPtr
@ -104,22 +106,7 @@ void DistinctStep::transformPipeline(QueryPipelineBuilder & pipeline, const Buil
return nullptr;
return std::make_shared<DistinctSortedChunkTransform>(
header, set_size_limits, limit_hint, distinct_sort_desc, columns);
});
return;
}
/// final distinct for sorted stream (sorting inside and among chunks)
if (input_stream.sort_mode == DataStream::SortMode::Stream)
{
assert(input_stream.has_single_port);
pipeline.addSimpleTransform(
[&](const Block & header, QueryPipelineBuilder::StreamType stream_type) -> ProcessorPtr
{
if (stream_type != QueryPipelineBuilder::StreamType::Main)
return nullptr;
return std::make_shared<DistinctSortedTransform>(header, distinct_sort_desc, set_size_limits, limit_hint, columns);
header, set_size_limits, limit_hint, distinct_sort_desc, columns, sorted_stream);
});
return;
}

49
src/Processors/Transforms/DistinctSortedChunkTransform.cpp
View File

@ -13,11 +13,13 @@ DistinctSortedChunkTransform::DistinctSortedChunkTransform(
const SizeLimits & output_size_limits_,
UInt64 limit_hint_,
const SortDescription & sorted_columns_descr_,
const Names & source_columns)
const Names & source_columns,
const bool sorted_stream_)
: ISimpleTransform(header_, header_, true)
, limit_hint(limit_hint_)
, output_size_limits(output_size_limits_)
, sorted_columns_descr(sorted_columns_descr_)
, sorted_stream(sorted_stream_)
{
/// calculate sorted columns positions
sorted_columns_pos.reserve(sorted_columns_descr.size());
@ -43,7 +45,7 @@ DistinctSortedChunkTransform::DistinctSortedChunkTransform(
/// reserve space in auxiliary column vectors for processing
sorted_columns.reserve(sorted_columns_pos.size());
other_columns.reserve(other_columns_pos.size());
current_key.reserve(sorted_columns.size());
prev_chunk_latest_key.reserve(sorted_columns.size());
}
void DistinctSortedChunkTransform::initChunkProcessing(const Columns & input_columns)
@ -101,28 +103,40 @@ size_t DistinctSortedChunkTransform::buildFilterForRange(
return count;
}
void DistinctSortedChunkTransform::setCurrentKey(const size_t row_pos)
void DistinctSortedChunkTransform::saveLatestKey(const size_t row_pos)
{
current_key.clear();
prev_chunk_latest_key.clear();
for (auto const & col : sorted_columns)
{
current_key.emplace_back(col->cloneEmpty());
current_key.back()->insertFrom(*col, row_pos);
prev_chunk_latest_key.emplace_back(col->cloneEmpty());
prev_chunk_latest_key.back()->insertFrom(*col, row_pos);
}
}
bool DistinctSortedChunkTransform::isCurrentKey(const size_t row_pos) const
bool DistinctSortedChunkTransform::isKey(const size_t key_pos, const size_t row_pos) const
{
for (size_t i = 0; i < sorted_columns.size(); ++i)
{
int res = current_key[i]->compareAt(0, row_pos, *sorted_columns[i], sorted_columns_descr[i].nulls_direction);
const int res = sorted_columns[i]->compareAt(key_pos, row_pos, *sorted_columns[i], sorted_columns_descr[i].nulls_direction);
if (res != 0)
return false;
}
return true;
}
size_t DistinctSortedChunkTransform::getRangeEnd(size_t begin, size_t end) const
bool DistinctSortedChunkTransform::isLatestKeyFromPrevChunk(const size_t row_pos) const
{
for (size_t i = 0; i < sorted_columns.size(); ++i)
{
const int res = prev_chunk_latest_key[i]->compareAt(0, row_pos, *sorted_columns[i], sorted_columns_descr[i].nulls_direction);
if (res != 0)
return false;
}
return true;
}
template<typename Predicate>
size_t DistinctSortedChunkTransform::getRangeEnd(size_t begin, size_t end, Predicate pred) const
{
assert(begin < end);
@ -133,7 +147,7 @@ size_t DistinctSortedChunkTransform::getRangeEnd(size_t begin, size_t end) const
for (size_t pos = begin; pos < linear_probe_end; ++pos)
{
if (!isCurrentKey(pos))
if (!pred(begin, pos))
return pos;
}
@ -142,7 +156,7 @@ size_t DistinctSortedChunkTransform::getRangeEnd(size_t begin, size_t end) const
while (low <= high)
{
size_t mid = low + (high - low) / 2;
if (isCurrentKey(mid))
if (pred(begin, mid))
low = mid + 1;
else
{
@ -155,13 +169,13 @@ size_t DistinctSortedChunkTransform::getRangeEnd(size_t begin, size_t end) const
std::pair<size_t, size_t> DistinctSortedChunkTransform::continueWithPrevRange(const size_t chunk_rows, IColumn::Filter & filter)
{
/// current_key is empty on very first transform() call
/// prev_chunk_latest_key is empty on very first transform() call
/// or first row doesn't match a key from previous transform()
if (current_key.empty() || !isCurrentKey(0))
if (prev_chunk_latest_key.empty() || !isLatestKeyFromPrevChunk(0))
return {0, 0};
size_t output_rows = 0;
const size_t range_end = getRangeEnd(0, chunk_rows);
const size_t range_end = getRangeEnd(0, chunk_rows, [&](size_t, size_t row_pos) { return isLatestKeyFromPrevChunk(row_pos); });
if (other_columns.empty())
std::fill(filter.begin(), filter.begin() + range_end, 0); /// skip rows already included in distinct on previous transform()
else
@ -191,11 +205,8 @@ void DistinctSortedChunkTransform::transform(Chunk & chunk)
size_t range_end = range_begin;
while (range_end != chunk_rows)
{
// set current key to find range
setCurrentKey(range_begin);
// find new range [range_begin, range_end)
range_end = getRangeEnd(range_begin, chunk_rows);
range_end = getRangeEnd(range_begin, chunk_rows, [&](size_t key_pos, size_t row_pos) { return isKey(key_pos, row_pos); });
// update filter for range
if (other_columns.empty())
@ -214,6 +225,8 @@ void DistinctSortedChunkTransform::transform(Chunk & chunk)
range_begin = range_end;
}
saveLatestKey(chunk_rows - 1);
/// apply the built filter
for (auto & input_column : input_columns)
input_column = input_column->filter(filter, output_rows);

16
src/Processors/Transforms/DistinctSortedChunkTransform.h
View File

@ -32,9 +32,10 @@ public:
const SizeLimits & output_size_limits_,
UInt64 limit_hint_,
const SortDescription & sorted_columns_descr_,
const Names & source_columns_);
const Names & source_columns_,
bool sorted_stream_);
String getName() const override { return "DistinctSortedChunkTransform"; }
String getName() const override { return (!sorted_stream ? "DistinctSortedChunkTransform" : "DistinctSortedStreamTransform"); }
protected:
void transform(Chunk & chunk) override;
@ -43,9 +44,11 @@ private:
void initChunkProcessing(const Columns & input_columns);
std::pair<size_t, size_t> continueWithPrevRange(size_t chunk_rows, IColumn::Filter & filter);
size_t ordinaryDistinctOnRange(IColumn::Filter & filter, size_t range_begin, size_t range_end, bool clear_data);
inline void setCurrentKey(size_t row_pos);
inline bool isCurrentKey(size_t row_pos) const;
inline size_t getRangeEnd(size_t range_begin, size_t range_end) const;
inline void saveLatestKey(size_t row_pos);
inline bool isLatestKeyFromPrevChunk(size_t row_pos) const;
inline bool isKey(size_t key_pos, size_t row_pos) const;
template<typename Predicate>
inline size_t getRangeEnd(size_t range_begin, size_t range_end, Predicate pred) const;
template <typename Method>
size_t buildFilterForRange(Method & method, IColumn::Filter & filter, size_t range_begin, size_t range_end, bool clear_data);
@ -66,7 +69,8 @@ private:
Sizes other_columns_sizes;
ColumnRawPtrs other_columns; // used during processing
MutableColumns current_key;
MutableColumns prev_chunk_latest_key;
const bool sorted_stream = false;
};
}

4
tests/queries/0_stateless/02317_distinct_in_order_optimization_explain.reference
View File

@ -7,13 +7,13 @@ DistinctSortedChunkTransform
-- distinct with primary key prefix -> pre-distinct optimization only
DistinctSortedChunkTransform
-- distinct with primary key prefix and order by on column in distinct -> pre-distinct and final distinct optimization
DistinctSortedTransform
DistinctSortedStreamTransform
DistinctSortedChunkTransform
-- distinct with primary key prefix and order by on column _not_ in distinct -> pre-distinct optimization only
DistinctSortedChunkTransform
-- distinct with non-primary key prefix -> no optimizations
No optimizations
-- distinct with non-primary key prefix and order by on column in distinct -> final distinct optimization only
DistinctSortedTransform
DistinctSortedStreamTransform
-- distinct with non-primary key prefix and order by on column _not_ in distinct -> no optimizations
No optimizations

2
tests/queries/0_stateless/02317_distinct_in_order_optimization_explain.sh
View File

@ -8,7 +8,7 @@ CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
DISABLE_OPTIMIZATION="set optimize_distinct_in_order=0"
ENABLE_OPTIMIZATION="set optimize_distinct_in_order=1"
GREP_OPTIMIZATIONS="grep 'DistinctSortedChunkTransform\|DistinctSortedTransform'"
GREP_OPTIMIZATIONS="grep 'DistinctSortedChunkTransform\|DistinctSortedStreamTransform'"
TRIM_LEADING_SPACES="sed -e 's/^[ \t]*//'"
FIND_OPTIMIZATIONS="$GREP_OPTIMIZATIONS | $TRIM_LEADING_SPACES"