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https://github.com/ClickHouse/ClickHouse.git
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1077 lines
36 KiB
C++
1077 lines
36 KiB
C++
#include <Storages/MergeTree/IMergeTreeReader.h>
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#include <Columns/FilterDescription.h>
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#include <Columns/ColumnsCommon.h>
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#include <base/range.h>
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#include <Interpreters/castColumn.h>
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#include <DataTypes/DataTypeNothing.h>
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#ifdef __SSE2__
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#include <emmintrin.h>
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#endif
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namespace DB
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{
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namespace ErrorCodes
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{
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extern const int LOGICAL_ERROR;
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extern const int BAD_ARGUMENTS;
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}
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static void filterColumns(Columns & columns, const IColumn::Filter & filter)
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{
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for (auto & column : columns)
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{
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if (column)
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{
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column = column->filter(filter, -1);
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if (column->empty())
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{
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columns.clear();
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return;
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}
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}
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}
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}
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static void filterColumns(Columns & columns, const ColumnPtr & filter)
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{
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ConstantFilterDescription const_descr(*filter);
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if (const_descr.always_true)
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return;
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if (const_descr.always_false)
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{
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for (auto & col : columns)
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if (col)
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col = col->cloneEmpty();
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return;
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}
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FilterDescription descr(*filter);
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filterColumns(columns, *descr.data);
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}
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static size_t getLastMark(const MergeTreeRangeReader::ReadResult::RangesInfo & ranges)
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{
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size_t current_task_last_mark = 0;
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for (const auto & mark_range : ranges)
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current_task_last_mark = std::max(current_task_last_mark, mark_range.range.end);
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return current_task_last_mark;
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}
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MergeTreeRangeReader::DelayedStream::DelayedStream(
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size_t from_mark,
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size_t current_task_last_mark_,
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IMergeTreeReader * merge_tree_reader_)
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: current_mark(from_mark), current_offset(0), num_delayed_rows(0)
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, current_task_last_mark(current_task_last_mark_)
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, merge_tree_reader(merge_tree_reader_)
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, index_granularity(&(merge_tree_reader->data_part->index_granularity))
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, continue_reading(false), is_finished(false)
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{
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}
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size_t MergeTreeRangeReader::DelayedStream::position() const
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{
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size_t num_rows_before_current_mark = index_granularity->getMarkStartingRow(current_mark);
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return num_rows_before_current_mark + current_offset + num_delayed_rows;
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}
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size_t MergeTreeRangeReader::DelayedStream::readRows(Columns & columns, size_t num_rows)
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{
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if (num_rows)
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{
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size_t rows_read = merge_tree_reader->readRows(
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current_mark, current_task_last_mark, continue_reading, num_rows, columns);
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continue_reading = true;
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/// Zero rows_read maybe either because reading has finished
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/// or because there is no columns we can read in current part (for example, all columns are default).
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/// In the last case we can't finish reading, but it's also ok for the first case
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/// because we can finish reading by calculation the number of pending rows.
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if (0 < rows_read && rows_read < num_rows)
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is_finished = true;
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return rows_read;
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}
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return 0;
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}
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size_t MergeTreeRangeReader::DelayedStream::read(Columns & columns, size_t from_mark, size_t offset, size_t num_rows)
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{
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size_t num_rows_before_from_mark = index_granularity->getMarkStartingRow(from_mark);
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/// We already stand accurately in required position,
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/// so because stream is lazy, we don't read anything
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/// and only increment amount delayed_rows
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if (position() == num_rows_before_from_mark + offset)
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{
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num_delayed_rows += num_rows;
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return 0;
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}
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else
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{
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size_t read_rows = finalize(columns);
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continue_reading = false;
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current_mark = from_mark;
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current_offset = offset;
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num_delayed_rows = num_rows;
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return read_rows;
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}
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}
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size_t MergeTreeRangeReader::DelayedStream::finalize(Columns & columns)
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{
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/// We need to skip some rows before reading
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if (current_offset && !continue_reading)
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{
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for (size_t mark_num : collections::range(current_mark, index_granularity->getMarksCount()))
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{
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size_t mark_index_granularity = index_granularity->getMarkRows(mark_num);
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if (current_offset >= mark_index_granularity)
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{
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current_offset -= mark_index_granularity;
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current_mark++;
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}
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else
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break;
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}
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/// Skip some rows from begin of granule.
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/// We don't know size of rows in compressed granule,
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/// so have to read them and throw out.
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if (current_offset)
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{
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Columns tmp_columns;
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tmp_columns.resize(columns.size());
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readRows(tmp_columns, current_offset);
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}
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}
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size_t rows_to_read = num_delayed_rows;
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current_offset += num_delayed_rows;
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num_delayed_rows = 0;
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return readRows(columns, rows_to_read);
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}
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MergeTreeRangeReader::Stream::Stream(
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size_t from_mark, size_t to_mark, size_t current_task_last_mark, IMergeTreeReader * merge_tree_reader_)
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: current_mark(from_mark), offset_after_current_mark(0)
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, last_mark(to_mark)
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, merge_tree_reader(merge_tree_reader_)
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, index_granularity(&(merge_tree_reader->data_part->index_granularity))
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, current_mark_index_granularity(index_granularity->getMarkRows(from_mark))
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, stream(from_mark, current_task_last_mark, merge_tree_reader)
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{
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size_t marks_count = index_granularity->getMarksCount();
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if (from_mark >= marks_count)
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throw Exception("Trying create stream to read from mark №"+ toString(current_mark) + " but total marks count is "
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+ toString(marks_count), ErrorCodes::LOGICAL_ERROR);
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if (last_mark > marks_count)
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throw Exception("Trying create stream to read to mark №"+ toString(current_mark) + " but total marks count is "
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+ toString(marks_count), ErrorCodes::LOGICAL_ERROR);
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}
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void MergeTreeRangeReader::Stream::checkNotFinished() const
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{
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if (isFinished())
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throw Exception("Cannot read out of marks range.", ErrorCodes::BAD_ARGUMENTS);
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}
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void MergeTreeRangeReader::Stream::checkEnoughSpaceInCurrentGranule(size_t num_rows) const
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{
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if (num_rows + offset_after_current_mark > current_mark_index_granularity)
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throw Exception("Cannot read from granule more than index_granularity.", ErrorCodes::LOGICAL_ERROR);
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}
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size_t MergeTreeRangeReader::Stream::readRows(Columns & columns, size_t num_rows)
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{
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size_t rows_read = stream.read(columns, current_mark, offset_after_current_mark, num_rows);
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if (stream.isFinished())
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finish();
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return rows_read;
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}
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void MergeTreeRangeReader::Stream::toNextMark()
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{
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++current_mark;
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size_t total_marks_count = index_granularity->getMarksCount();
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if (current_mark < total_marks_count)
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current_mark_index_granularity = index_granularity->getMarkRows(current_mark);
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else if (current_mark == total_marks_count)
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current_mark_index_granularity = 0; /// HACK?
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else
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throw Exception("Trying to read from mark " + toString(current_mark) + ", but total marks count " + toString(total_marks_count), ErrorCodes::LOGICAL_ERROR);
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offset_after_current_mark = 0;
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}
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size_t MergeTreeRangeReader::Stream::read(Columns & columns, size_t num_rows, bool skip_remaining_rows_in_current_granule)
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{
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checkEnoughSpaceInCurrentGranule(num_rows);
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if (num_rows)
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{
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checkNotFinished();
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size_t read_rows = readRows(columns, num_rows);
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offset_after_current_mark += num_rows;
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/// Start new granule; skipped_rows_after_offset is already zero.
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if (offset_after_current_mark == current_mark_index_granularity || skip_remaining_rows_in_current_granule)
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toNextMark();
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return read_rows;
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}
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else
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{
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/// Nothing to read.
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if (skip_remaining_rows_in_current_granule)
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{
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/// Skip the rest of the rows in granule and start new one.
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checkNotFinished();
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toNextMark();
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}
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return 0;
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}
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}
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void MergeTreeRangeReader::Stream::skip(size_t num_rows)
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{
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if (num_rows)
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{
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checkNotFinished();
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checkEnoughSpaceInCurrentGranule(num_rows);
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offset_after_current_mark += num_rows;
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if (offset_after_current_mark == current_mark_index_granularity)
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{
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/// Start new granule; skipped_rows_after_offset is already zero.
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toNextMark();
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}
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}
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}
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size_t MergeTreeRangeReader::Stream::finalize(Columns & columns)
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{
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size_t read_rows = stream.finalize(columns);
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if (stream.isFinished())
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finish();
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return read_rows;
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}
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void MergeTreeRangeReader::ReadResult::addGranule(size_t num_rows_)
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{
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rows_per_granule.push_back(num_rows_);
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total_rows_per_granule += num_rows_;
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}
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void MergeTreeRangeReader::ReadResult::adjustLastGranule()
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{
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size_t num_rows_to_subtract = total_rows_per_granule - num_read_rows;
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if (rows_per_granule.empty())
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throw Exception("Can't adjust last granule because no granules were added", ErrorCodes::LOGICAL_ERROR);
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if (num_rows_to_subtract > rows_per_granule.back())
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throw Exception(ErrorCodes::LOGICAL_ERROR,
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"Can't adjust last granule because it has {} rows, but try to subtract {} rows.",
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toString(rows_per_granule.back()), toString(num_rows_to_subtract));
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rows_per_granule.back() -= num_rows_to_subtract;
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total_rows_per_granule -= num_rows_to_subtract;
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}
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void MergeTreeRangeReader::ReadResult::clear()
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{
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/// Need to save information about the number of granules.
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num_rows_to_skip_in_last_granule += rows_per_granule.back();
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rows_per_granule.assign(rows_per_granule.size(), 0);
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total_rows_per_granule = 0;
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filter_holder = nullptr;
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filter = nullptr;
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}
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void MergeTreeRangeReader::ReadResult::shrink(Columns & old_columns)
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{
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for (auto & column : old_columns)
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{
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if (!column)
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continue;
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if (const auto * column_const = typeid_cast<const ColumnConst *>(column.get()))
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{
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column = column_const->cloneResized(total_rows_per_granule);
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continue;
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}
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auto new_column = column->cloneEmpty();
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new_column->reserve(total_rows_per_granule);
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for (size_t j = 0, pos = 0; j < rows_per_granule_original.size(); pos += rows_per_granule_original[j++])
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{
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if (rows_per_granule[j])
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new_column->insertRangeFrom(*column, pos, rows_per_granule[j]);
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}
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column = std::move(new_column);
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}
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}
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void MergeTreeRangeReader::ReadResult::setFilterConstTrue()
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{
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clearFilter();
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filter_holder = DataTypeUInt8().createColumnConst(num_rows, 1u);
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}
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void MergeTreeRangeReader::ReadResult::setFilterConstFalse()
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{
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clearFilter();
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columns.clear();
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num_rows = 0;
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}
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void MergeTreeRangeReader::ReadResult::optimize(bool can_read_incomplete_granules, bool allow_filter_columns)
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{
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if (total_rows_per_granule == 0 || filter == nullptr)
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return;
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NumRows zero_tails;
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auto total_zero_rows_in_tails = countZeroTails(filter->getData(), zero_tails, can_read_incomplete_granules);
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if (total_zero_rows_in_tails == filter->size())
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{
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clear();
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return;
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}
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else if (total_zero_rows_in_tails == 0 && countBytesInResultFilter(filter->getData()) == filter->size())
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{
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setFilterConstTrue();
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return;
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}
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/// Just a guess. If only a few rows may be skipped, it's better not to skip at all.
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else if (2 * total_zero_rows_in_tails > filter->size())
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{
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for (auto i : collections::range(0, rows_per_granule.size()))
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{
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rows_per_granule_original.push_back(rows_per_granule[i]);
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rows_per_granule[i] -= zero_tails[i];
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}
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num_rows_to_skip_in_last_granule += rows_per_granule_original.back() - rows_per_granule.back();
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filter_original = filter;
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filter_holder_original = std::move(filter_holder);
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/// Check if const 1 after shrink
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if (allow_filter_columns && countBytesInResultFilter(filter->getData()) + total_zero_rows_in_tails == total_rows_per_granule)
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{
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total_rows_per_granule = total_rows_per_granule - total_zero_rows_in_tails;
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num_rows = total_rows_per_granule;
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setFilterConstTrue();
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shrink(columns); /// shrink acts as filtering in such case
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}
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else
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{
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auto new_filter = ColumnUInt8::create(filter->size() - total_zero_rows_in_tails);
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IColumn::Filter & new_data = new_filter->getData();
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collapseZeroTails(filter->getData(), new_data);
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total_rows_per_granule = new_filter->size();
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num_rows = total_rows_per_granule;
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filter = new_filter.get();
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filter_holder = std::move(new_filter);
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}
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need_filter = true;
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}
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/// Another guess, if it's worth filtering at PREWHERE
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else if (countBytesInResultFilter(filter->getData()) < 0.6 * filter->size())
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need_filter = true;
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}
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size_t MergeTreeRangeReader::ReadResult::countZeroTails(const IColumn::Filter & filter_vec, NumRows & zero_tails, bool can_read_incomplete_granules) const
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{
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zero_tails.resize(0);
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zero_tails.reserve(rows_per_granule.size());
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const auto * filter_data = filter_vec.data();
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size_t total_zero_rows_in_tails = 0;
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for (auto rows_to_read : rows_per_granule)
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{
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/// Count the number of zeros at the end of filter for rows were read from current granule.
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size_t zero_tail = numZerosInTail(filter_data, filter_data + rows_to_read);
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if (!can_read_incomplete_granules && zero_tail != rows_to_read)
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zero_tail = 0;
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zero_tails.push_back(zero_tail);
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total_zero_rows_in_tails += zero_tails.back();
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filter_data += rows_to_read;
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}
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return total_zero_rows_in_tails;
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}
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void MergeTreeRangeReader::ReadResult::collapseZeroTails(const IColumn::Filter & filter_vec, IColumn::Filter & new_filter_vec)
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{
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const auto * filter_data = filter_vec.data();
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auto * new_filter_data = new_filter_vec.data();
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for (auto i : collections::range(0, rows_per_granule.size()))
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{
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memcpySmallAllowReadWriteOverflow15(new_filter_data, filter_data, rows_per_granule[i]);
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filter_data += rows_per_granule_original[i];
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new_filter_data += rows_per_granule[i];
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}
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new_filter_vec.resize(new_filter_data - new_filter_vec.data());
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}
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size_t MergeTreeRangeReader::ReadResult::numZerosInTail(const UInt8 * begin, const UInt8 * end)
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{
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size_t count = 0;
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#if defined(__SSE2__) && defined(__POPCNT__)
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const __m128i zero16 = _mm_setzero_si128();
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while (end - begin >= 64)
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{
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end -= 64;
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const auto * pos = end;
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UInt64 val =
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static_cast<UInt64>(_mm_movemask_epi8(_mm_cmpeq_epi8(
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_mm_loadu_si128(reinterpret_cast<const __m128i *>(pos)),
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zero16)))
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| (static_cast<UInt64>(_mm_movemask_epi8(_mm_cmpeq_epi8(
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_mm_loadu_si128(reinterpret_cast<const __m128i *>(pos + 16)),
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zero16))) << 16u)
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| (static_cast<UInt64>(_mm_movemask_epi8(_mm_cmpeq_epi8(
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_mm_loadu_si128(reinterpret_cast<const __m128i *>(pos + 32)),
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zero16))) << 32u)
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_mm_loadu_si128(reinterpret_cast<const __m128i *>(pos + 48)),
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zero16))) << 48u);
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val = ~val;
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if (val == 0)
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count += 64;
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else
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{
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count += __builtin_clzll(val);
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return count;
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}
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}
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#endif
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while (end > begin && *(--end) == 0)
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{
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++count;
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}
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return count;
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}
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void MergeTreeRangeReader::ReadResult::setFilter(const ColumnPtr & new_filter)
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{
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if (!new_filter && filter)
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throw Exception("Can't replace existing filter with empty.", ErrorCodes::LOGICAL_ERROR);
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if (filter)
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{
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size_t new_size = new_filter->size();
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if (new_size != total_rows_per_granule)
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throw Exception("Can't set filter because it's size is " + toString(new_size) + " but "
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+ toString(total_rows_per_granule) + " rows was read.", ErrorCodes::LOGICAL_ERROR);
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}
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|
|
ConstantFilterDescription const_description(*new_filter);
|
|
if (const_description.always_true)
|
|
{
|
|
setFilterConstTrue();
|
|
}
|
|
else if (const_description.always_false)
|
|
{
|
|
clear();
|
|
}
|
|
else
|
|
{
|
|
FilterDescription filter_description(*new_filter);
|
|
filter_holder = filter_description.data_holder ? filter_description.data_holder : new_filter;
|
|
filter = typeid_cast<const ColumnUInt8 *>(filter_holder.get());
|
|
if (!filter)
|
|
throw Exception("setFilter function expected ColumnUInt8.", ErrorCodes::LOGICAL_ERROR);
|
|
}
|
|
}
|
|
|
|
|
|
size_t MergeTreeRangeReader::ReadResult::countBytesInResultFilter(const IColumn::Filter & filter_)
|
|
{
|
|
auto it = filter_bytes_map.find(&filter_);
|
|
if (it == filter_bytes_map.end())
|
|
{
|
|
auto bytes = countBytesInFilter(filter_);
|
|
filter_bytes_map[&filter_] = bytes;
|
|
return bytes;
|
|
}
|
|
else
|
|
return it->second;
|
|
}
|
|
|
|
MergeTreeRangeReader::MergeTreeRangeReader(
|
|
IMergeTreeReader * merge_tree_reader_,
|
|
MergeTreeRangeReader * prev_reader_,
|
|
const PrewhereExprInfo * prewhere_info_,
|
|
bool last_reader_in_chain_)
|
|
: merge_tree_reader(merge_tree_reader_)
|
|
, index_granularity(&(merge_tree_reader->data_part->index_granularity))
|
|
, prev_reader(prev_reader_)
|
|
, prewhere_info(prewhere_info_)
|
|
, last_reader_in_chain(last_reader_in_chain_)
|
|
, is_initialized(true)
|
|
{
|
|
if (prev_reader)
|
|
sample_block = prev_reader->getSampleBlock();
|
|
|
|
for (const auto & name_and_type : merge_tree_reader->getColumns())
|
|
sample_block.insert({name_and_type.type->createColumn(), name_and_type.type, name_and_type.name});
|
|
|
|
if (prewhere_info)
|
|
{
|
|
if (prewhere_info->alias_actions)
|
|
prewhere_info->alias_actions->execute(sample_block, true);
|
|
|
|
if (prewhere_info->row_level_filter)
|
|
{
|
|
prewhere_info->row_level_filter->execute(sample_block, true);
|
|
sample_block.erase(prewhere_info->row_level_column_name);
|
|
}
|
|
|
|
if (prewhere_info->prewhere_actions)
|
|
prewhere_info->prewhere_actions->execute(sample_block, true);
|
|
|
|
if (prewhere_info->remove_prewhere_column)
|
|
sample_block.erase(prewhere_info->prewhere_column_name);
|
|
}
|
|
}
|
|
|
|
bool MergeTreeRangeReader::isReadingFinished() const
|
|
{
|
|
return prev_reader ? prev_reader->isReadingFinished() : stream.isFinished();
|
|
}
|
|
|
|
size_t MergeTreeRangeReader::numReadRowsInCurrentGranule() const
|
|
{
|
|
return prev_reader ? prev_reader->numReadRowsInCurrentGranule() : stream.numReadRowsInCurrentGranule();
|
|
}
|
|
|
|
size_t MergeTreeRangeReader::numPendingRowsInCurrentGranule() const
|
|
{
|
|
if (prev_reader)
|
|
return prev_reader->numPendingRowsInCurrentGranule();
|
|
|
|
auto pending_rows = stream.numPendingRowsInCurrentGranule();
|
|
|
|
if (pending_rows)
|
|
return pending_rows;
|
|
|
|
return numRowsInCurrentGranule();
|
|
}
|
|
|
|
|
|
size_t MergeTreeRangeReader::numRowsInCurrentGranule() const
|
|
{
|
|
/// If pending_rows is zero, than stream is not initialized.
|
|
if (stream.current_mark_index_granularity)
|
|
return stream.current_mark_index_granularity;
|
|
|
|
/// We haven't read anything, return first
|
|
size_t first_mark = merge_tree_reader->getFirstMarkToRead();
|
|
return index_granularity->getMarkRows(first_mark);
|
|
}
|
|
|
|
size_t MergeTreeRangeReader::currentMark() const
|
|
{
|
|
return stream.currentMark();
|
|
}
|
|
|
|
size_t MergeTreeRangeReader::Stream::numPendingRows() const
|
|
{
|
|
size_t rows_between_marks = index_granularity->getRowsCountInRange(current_mark, last_mark);
|
|
return rows_between_marks - offset_after_current_mark;
|
|
}
|
|
|
|
|
|
size_t MergeTreeRangeReader::Stream::ceilRowsToCompleteGranules(size_t rows_num) const
|
|
{
|
|
/// FIXME suboptimal
|
|
size_t result = 0;
|
|
size_t from_mark = current_mark;
|
|
while (result < rows_num && from_mark < last_mark)
|
|
result += index_granularity->getMarkRows(from_mark++);
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
bool MergeTreeRangeReader::isCurrentRangeFinished() const
|
|
{
|
|
return prev_reader ? prev_reader->isCurrentRangeFinished() : stream.isFinished();
|
|
}
|
|
|
|
MergeTreeRangeReader::ReadResult MergeTreeRangeReader::read(size_t max_rows, MarkRanges & ranges)
|
|
{
|
|
if (max_rows == 0)
|
|
throw Exception("Expected at least 1 row to read, got 0.", ErrorCodes::LOGICAL_ERROR);
|
|
|
|
ReadResult read_result;
|
|
|
|
if (prev_reader)
|
|
{
|
|
read_result = prev_reader->read(max_rows, ranges);
|
|
|
|
size_t num_read_rows;
|
|
Columns columns = continueReadingChain(read_result, num_read_rows);
|
|
|
|
/// Nothing to do. Return empty result.
|
|
if (read_result.num_rows == 0)
|
|
return read_result;
|
|
|
|
bool has_columns = false;
|
|
size_t total_bytes = 0;
|
|
for (auto & column : columns)
|
|
{
|
|
if (column)
|
|
{
|
|
total_bytes += column->byteSize();
|
|
has_columns = true;
|
|
}
|
|
}
|
|
|
|
read_result.addNumBytesRead(total_bytes);
|
|
|
|
bool should_evaluate_missing_defaults = false;
|
|
|
|
if (has_columns)
|
|
{
|
|
/// num_read_rows >= read_result.num_rows
|
|
/// We must filter block before adding columns to read_result.block
|
|
|
|
/// Fill missing columns before filtering because some arrays from Nested may have empty data.
|
|
merge_tree_reader->fillMissingColumns(columns, should_evaluate_missing_defaults, num_read_rows);
|
|
|
|
if (read_result.getFilter())
|
|
filterColumns(columns, read_result.getFilter()->getData());
|
|
}
|
|
else
|
|
{
|
|
size_t num_rows = read_result.num_rows;
|
|
|
|
/// If block is empty, we still may need to add missing columns.
|
|
/// In that case use number of rows in result block and don't filter block.
|
|
if (num_rows)
|
|
merge_tree_reader->fillMissingColumns(columns, should_evaluate_missing_defaults, num_rows);
|
|
}
|
|
|
|
if (!columns.empty())
|
|
{
|
|
/// If some columns absent in part, then evaluate default values
|
|
if (should_evaluate_missing_defaults)
|
|
{
|
|
auto block = prev_reader->sample_block.cloneWithColumns(read_result.columns);
|
|
auto block_before_prewhere = read_result.block_before_prewhere;
|
|
for (auto & ctn : block)
|
|
{
|
|
if (block_before_prewhere.has(ctn.name))
|
|
block_before_prewhere.erase(ctn.name);
|
|
}
|
|
|
|
if (block_before_prewhere)
|
|
{
|
|
if (read_result.need_filter)
|
|
{
|
|
auto old_columns = block_before_prewhere.getColumns();
|
|
filterColumns(old_columns, read_result.getFilterOriginal()->getData());
|
|
block_before_prewhere.setColumns(std::move(old_columns));
|
|
}
|
|
|
|
for (auto && ctn : block_before_prewhere)
|
|
block.insert(std::move(ctn));
|
|
}
|
|
merge_tree_reader->evaluateMissingDefaults(block, columns);
|
|
}
|
|
/// If columns not empty, then apply on-fly alter conversions if any required
|
|
merge_tree_reader->performRequiredConversions(columns);
|
|
}
|
|
|
|
read_result.columns.reserve(read_result.columns.size() + columns.size());
|
|
for (auto & column : columns)
|
|
read_result.columns.emplace_back(std::move(column));
|
|
}
|
|
else
|
|
{
|
|
read_result = startReadingChain(max_rows, ranges);
|
|
read_result.num_rows = read_result.numReadRows();
|
|
|
|
if (read_result.num_rows)
|
|
{
|
|
bool should_evaluate_missing_defaults;
|
|
merge_tree_reader->fillMissingColumns(read_result.columns, should_evaluate_missing_defaults,
|
|
read_result.num_rows);
|
|
|
|
/// If some columns absent in part, then evaluate default values
|
|
if (should_evaluate_missing_defaults)
|
|
merge_tree_reader->evaluateMissingDefaults({}, read_result.columns);
|
|
|
|
/// If result not empty, then apply on-fly alter conversions if any required
|
|
merge_tree_reader->performRequiredConversions(read_result.columns);
|
|
}
|
|
else
|
|
read_result.columns.clear();
|
|
|
|
size_t total_bytes = 0;
|
|
for (auto & column : read_result.columns)
|
|
total_bytes += column->byteSize();
|
|
|
|
read_result.addNumBytesRead(total_bytes);
|
|
}
|
|
|
|
if (read_result.num_rows == 0)
|
|
return read_result;
|
|
|
|
executePrewhereActionsAndFilterColumns(read_result);
|
|
|
|
return read_result;
|
|
}
|
|
|
|
|
|
MergeTreeRangeReader::ReadResult MergeTreeRangeReader::startReadingChain(size_t max_rows, MarkRanges & ranges)
|
|
{
|
|
ReadResult result;
|
|
result.columns.resize(merge_tree_reader->getColumns().size());
|
|
|
|
size_t current_task_last_mark = getLastMark(ranges);
|
|
|
|
/// Stream is lazy. result.num_added_rows is the number of rows added to block which is not equal to
|
|
/// result.num_rows_read until call to stream.finalize(). Also result.num_added_rows may be less than
|
|
/// result.num_rows_read if the last granule in range also the last in part (so we have to adjust last granule).
|
|
{
|
|
size_t space_left = max_rows;
|
|
while (space_left && (!stream.isFinished() || !ranges.empty()))
|
|
{
|
|
if (stream.isFinished())
|
|
{
|
|
result.addRows(stream.finalize(result.columns));
|
|
stream = Stream(ranges.front().begin, ranges.front().end, current_task_last_mark, merge_tree_reader);
|
|
result.addRange(ranges.front());
|
|
ranges.pop_front();
|
|
}
|
|
|
|
size_t current_space = space_left;
|
|
|
|
/// If reader can't read part of granule, we have to increase number of reading rows
|
|
/// to read complete granules and exceed max_rows a bit.
|
|
if (!merge_tree_reader->canReadIncompleteGranules())
|
|
current_space = stream.ceilRowsToCompleteGranules(space_left);
|
|
|
|
auto rows_to_read = std::min(current_space, stream.numPendingRowsInCurrentGranule());
|
|
|
|
bool last = rows_to_read == space_left;
|
|
result.addRows(stream.read(result.columns, rows_to_read, !last));
|
|
result.addGranule(rows_to_read);
|
|
space_left = (rows_to_read > space_left ? 0 : space_left - rows_to_read);
|
|
}
|
|
}
|
|
|
|
result.addRows(stream.finalize(result.columns));
|
|
|
|
/// Last granule may be incomplete.
|
|
result.adjustLastGranule();
|
|
|
|
return result;
|
|
}
|
|
|
|
Columns MergeTreeRangeReader::continueReadingChain(ReadResult & result, size_t & num_rows)
|
|
{
|
|
Columns columns;
|
|
num_rows = 0;
|
|
|
|
if (result.rowsPerGranule().empty())
|
|
{
|
|
/// If zero rows were read on prev step, than there is no more rows to read.
|
|
/// Last granule may have less rows than index_granularity, so finish reading manually.
|
|
stream.finish();
|
|
return columns;
|
|
}
|
|
|
|
columns.resize(merge_tree_reader->numColumnsInResult());
|
|
|
|
const auto & rows_per_granule = result.rowsPerGranule();
|
|
const auto & started_ranges = result.startedRanges();
|
|
|
|
size_t current_task_last_mark = getLastMark(started_ranges);
|
|
size_t next_range_to_start = 0;
|
|
|
|
auto size = rows_per_granule.size();
|
|
for (auto i : collections::range(0, size))
|
|
{
|
|
if (next_range_to_start < started_ranges.size()
|
|
&& i == started_ranges[next_range_to_start].num_granules_read_before_start)
|
|
{
|
|
num_rows += stream.finalize(columns);
|
|
const auto & range = started_ranges[next_range_to_start].range;
|
|
++next_range_to_start;
|
|
stream = Stream(range.begin, range.end, current_task_last_mark, merge_tree_reader);
|
|
}
|
|
|
|
bool last = i + 1 == size;
|
|
num_rows += stream.read(columns, rows_per_granule[i], !last);
|
|
}
|
|
|
|
stream.skip(result.numRowsToSkipInLastGranule());
|
|
num_rows += stream.finalize(columns);
|
|
|
|
/// added_rows may be zero if all columns were read in prewhere and it's ok.
|
|
if (num_rows && num_rows != result.totalRowsPerGranule())
|
|
throw Exception("RangeReader read " + toString(num_rows) + " rows, but "
|
|
+ toString(result.totalRowsPerGranule()) + " expected.", ErrorCodes::LOGICAL_ERROR);
|
|
|
|
return columns;
|
|
}
|
|
|
|
static void checkCombinedFiltersSize(size_t bytes_in_first_filter, size_t second_filter_size)
|
|
{
|
|
if (bytes_in_first_filter != second_filter_size)
|
|
throw Exception(ErrorCodes::LOGICAL_ERROR,
|
|
"Cannot combine filters because number of bytes in a first filter ({}) "
|
|
"does not match second filter size ({})", bytes_in_first_filter, second_filter_size);
|
|
}
|
|
|
|
static ColumnPtr combineFilters(ColumnPtr first, ColumnPtr second)
|
|
{
|
|
ConstantFilterDescription first_const_descr(*first);
|
|
|
|
if (first_const_descr.always_true)
|
|
{
|
|
checkCombinedFiltersSize(first->size(), second->size());
|
|
return second;
|
|
}
|
|
|
|
if (first_const_descr.always_false)
|
|
{
|
|
checkCombinedFiltersSize(0, second->size());
|
|
return first;
|
|
}
|
|
|
|
FilterDescription first_descr(*first);
|
|
|
|
size_t bytes_in_first_filter = countBytesInFilter(*first_descr.data);
|
|
checkCombinedFiltersSize(bytes_in_first_filter, second->size());
|
|
|
|
ConstantFilterDescription second_const_descr(*second);
|
|
|
|
if (second_const_descr.always_true)
|
|
return first;
|
|
|
|
if (second_const_descr.always_false)
|
|
return second->cloneResized(first->size());
|
|
|
|
FilterDescription second_descr(*second);
|
|
|
|
MutableColumnPtr mut_first;
|
|
if (first_descr.data_holder)
|
|
mut_first = IColumn::mutate(std::move(first_descr.data_holder));
|
|
else
|
|
mut_first = IColumn::mutate(std::move(first));
|
|
|
|
auto & first_data = typeid_cast<ColumnUInt8 *>(mut_first.get())->getData();
|
|
const auto * second_data = second_descr.data->data();
|
|
|
|
for (auto & val : first_data)
|
|
{
|
|
if (val)
|
|
{
|
|
val = *second_data;
|
|
++second_data;
|
|
}
|
|
}
|
|
|
|
return mut_first;
|
|
}
|
|
|
|
void MergeTreeRangeReader::executePrewhereActionsAndFilterColumns(ReadResult & result)
|
|
{
|
|
if (!prewhere_info)
|
|
return;
|
|
|
|
const auto & header = merge_tree_reader->getColumns();
|
|
size_t num_columns = header.size();
|
|
|
|
if (result.columns.size() != num_columns)
|
|
throw Exception("Invalid number of columns passed to MergeTreeRangeReader. "
|
|
"Expected " + toString(num_columns) + ", "
|
|
"got " + toString(result.columns.size()), ErrorCodes::LOGICAL_ERROR);
|
|
|
|
ColumnPtr filter;
|
|
ColumnPtr row_level_filter;
|
|
size_t prewhere_column_pos;
|
|
|
|
{
|
|
/// Restore block from columns list.
|
|
Block block;
|
|
size_t pos = 0;
|
|
|
|
if (prev_reader)
|
|
{
|
|
for (const auto & col : prev_reader->getSampleBlock())
|
|
{
|
|
block.insert({result.columns[pos], col.type, col.name});
|
|
++pos;
|
|
}
|
|
}
|
|
|
|
for (auto name_and_type = header.begin(); pos < num_columns; ++pos, ++name_and_type)
|
|
block.insert({result.columns[pos], name_and_type->type, name_and_type->name});
|
|
|
|
if (prewhere_info->alias_actions)
|
|
prewhere_info->alias_actions->execute(block);
|
|
|
|
/// Columns might be projected out. We need to store them here so that default columns can be evaluated later.
|
|
result.block_before_prewhere = block;
|
|
|
|
if (prewhere_info->row_level_filter)
|
|
{
|
|
prewhere_info->row_level_filter->execute(block);
|
|
auto row_level_filter_pos = block.getPositionByName(prewhere_info->row_level_column_name);
|
|
row_level_filter = block.getByPosition(row_level_filter_pos).column;
|
|
block.erase(row_level_filter_pos);
|
|
|
|
auto columns = block.getColumns();
|
|
filterColumns(columns, row_level_filter);
|
|
if (columns.empty())
|
|
block = block.cloneEmpty();
|
|
else
|
|
block.setColumns(columns);
|
|
}
|
|
|
|
prewhere_info->prewhere_actions->execute(block);
|
|
|
|
prewhere_column_pos = block.getPositionByName(prewhere_info->prewhere_column_name);
|
|
|
|
result.columns.clear();
|
|
result.columns.reserve(block.columns());
|
|
for (auto & col : block)
|
|
result.columns.emplace_back(std::move(col.column));
|
|
|
|
filter.swap(result.columns[prewhere_column_pos]);
|
|
}
|
|
|
|
if (result.getFilter())
|
|
{
|
|
/// TODO: implement for prewhere chain.
|
|
/// In order to do it we need combine filter and result.filter, where filter filters only '1' in result.filter.
|
|
throw Exception("MergeTreeRangeReader chain with several prewhere actions in not implemented.",
|
|
ErrorCodes::LOGICAL_ERROR);
|
|
}
|
|
|
|
if (filter && row_level_filter)
|
|
{
|
|
row_level_filter = combineFilters(std::move(row_level_filter), filter);
|
|
result.setFilter(row_level_filter);
|
|
}
|
|
else
|
|
result.setFilter(filter);
|
|
|
|
/// If there is a WHERE, we filter in there, and only optimize IO and shrink columns here
|
|
if (!last_reader_in_chain)
|
|
result.optimize(merge_tree_reader->canReadIncompleteGranules(), prewhere_info->row_level_filter == nullptr);
|
|
|
|
/// If we read nothing or filter gets optimized to nothing
|
|
if (result.totalRowsPerGranule() == 0)
|
|
result.setFilterConstFalse();
|
|
/// If we need to filter in PREWHERE
|
|
else if (prewhere_info->need_filter || result.need_filter || prewhere_info->row_level_filter)
|
|
{
|
|
/// If there is a filter and without optimized
|
|
if (result.getFilter() && last_reader_in_chain)
|
|
{
|
|
const auto * result_filter = result.getFilter();
|
|
/// optimize is not called, need to check const 1 and const 0
|
|
size_t bytes_in_filter = result.countBytesInResultFilter(result_filter->getData());
|
|
if (bytes_in_filter == 0)
|
|
result.setFilterConstFalse();
|
|
else if (bytes_in_filter == result.num_rows)
|
|
result.setFilterConstTrue();
|
|
}
|
|
|
|
/// If there is still a filter, do the filtering now
|
|
if (result.getFilter())
|
|
{
|
|
/// filter might be shrunk while columns not
|
|
const auto * result_filter = result.getFilterOriginal();
|
|
|
|
if (row_level_filter)
|
|
filterColumns(result.columns, filter);
|
|
else
|
|
filterColumns(result.columns, result_filter->getData());
|
|
|
|
result.need_filter = true;
|
|
|
|
bool has_column = false;
|
|
for (auto & column : result.columns)
|
|
{
|
|
if (column)
|
|
{
|
|
has_column = true;
|
|
result.num_rows = column->size();
|
|
break;
|
|
}
|
|
}
|
|
|
|
/// There is only one filter column. Record the actual number
|
|
if (!has_column)
|
|
result.num_rows = result.countBytesInResultFilter(result_filter->getData());
|
|
}
|
|
|
|
/// Check if the PREWHERE column is needed
|
|
if (!result.columns.empty())
|
|
{
|
|
if (prewhere_info->remove_prewhere_column)
|
|
result.columns.erase(result.columns.begin() + prewhere_column_pos);
|
|
else
|
|
result.columns[prewhere_column_pos] =
|
|
getSampleBlock().getByName(prewhere_info->prewhere_column_name).type->
|
|
createColumnConst(result.num_rows, 1u)->convertToFullColumnIfConst();
|
|
}
|
|
}
|
|
/// Filter in WHERE instead
|
|
else
|
|
{
|
|
if (prewhere_info->remove_prewhere_column)
|
|
result.columns.erase(result.columns.begin() + prewhere_column_pos);
|
|
else
|
|
{
|
|
auto type = getSampleBlock().getByName(prewhere_info->prewhere_column_name).type;
|
|
ColumnWithTypeAndName col(result.getFilterHolder()->convertToFullColumnIfConst(), std::make_shared<DataTypeUInt8>(), "");
|
|
result.columns[prewhere_column_pos] = castColumn(col, type);
|
|
result.clearFilter(); // Acting as a flag to not filter in PREWHERE
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|