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Nikolai Kochetov 2017-07-21 21:02:02 +03:00
parent c64b65ee29
commit bc0921a64e
1 changed files with 4 additions and 0 deletions
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4
dbms/src/Storages/MergeTree/MergeTreeBaseBlockInputStream.cpp
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@ -87,15 +87,19 @@ Block MergeTreeBaseBlockInputStream::readFromPart()
if (!task.size_predictor)
return max_block_size_rows;
/// Limit in rows, calculated by preferred_max_column_in_block_size_bytes. Can't be less than index_granularity.
size_t rows_to_read = std::max(index_granularity, task.size_predictor->estimateNumRows(preferred_block_size_bytes));
if (preferred_max_column_in_block_size_bytes)
{
/// Limit in rows, calculated by preferred_max_column_in_block_size_bytes.
size_t rows_to_read_for_max_size_column
= task.size_predictor->estimateNumRowsForMaxSizeColumn(preferred_max_column_in_block_size_bytes);
double filtration_ratio = std::max(min_filtration_ratio, 1.0 - task.size_predictor->filtered_rows_ratio);
size_t rows_to_read_for_max_size_column_with_filtration
= static_cast<size_t>(rows_to_read_for_max_size_column / filtration_ratio);
/// If preferred_max_column_in_block_size_bytes is used, number of rows to read can be less than index_granularity.
rows_to_read = std::min(rows_to_read, rows_to_read_for_max_size_column_with_filtration);
}