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Merge remote-tracking branch 'upstream/master' into METR-23466

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This commit is contained in:
proller 2016-11-27 15:03:35 +03:00
commit 4c90ffd61d
1 changed files with 13 additions and 17 deletions
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30
dbms/src/Storages/MergeTree/SimpleMergeSelector.cpp
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@ -16,26 +16,22 @@ struct Estimator
{
using Iterator = SimpleMergeSelector::PartsInPartition::const_iterator;
void consider(Iterator begin, Iterator end, size_t sum_size, size_t size_next_at_left, size_t size_next_at_right)
void consider(Iterator begin, Iterator end, size_t sum_size, size_t size_prev_at_left)
{
double current_score = score(end - begin, sum_size);
if (size_next_at_left > sum_size * 0.9)
if (size_prev_at_left > sum_size * 0.9)
{
double difference = std::abs(log2(static_cast<double>(sum_size) / size_next_at_left));
double difference = std::abs(log2(static_cast<double>(sum_size) / size_prev_at_left));
if (difference < 0.5)
current_score *= 0.75 + difference * 0.5;
}
if (size_next_at_right == 0)
current_score *= 0.9;
if (size_next_at_right > sum_size * 0.9)
{
double difference = std::abs(log2(static_cast<double>(sum_size) / size_next_at_right));
if (difference < 0.5)
current_score *= 0.75 + difference * 0.5;
}
/** Heuristic:
* From right side of range, remove all parts, that size is less than 1% of sum_size.
*/
while (end >= begin + 3 && (end - 1)->size < 0.01 * sum_size)
--end;
if (!min_score || current_score < min_score)
{
@ -105,9 +101,10 @@ void selectWithinPartition(
if (settings.max_parts_to_merge_at_once && end - begin > settings.max_parts_to_merge_at_once)
break;
sum_size += parts[end - 1].size;
if (parts[end - 1].size > max_size)
max_size = parts[end - 1].size;
size_t cur_size = parts[end - 1].size;
sum_size += cur_size;
max_size = std::max(max_size, cur_size);
if (max_total_size_to_merge && sum_size > max_total_size_to_merge)
break;
@ -117,8 +114,7 @@ void selectWithinPartition(
parts.begin() + begin,
parts.begin() + end,
sum_size,
begin == 0 ? 0 : parts[begin - 1].size,
end == parts_count ? 0 : parts[end].size);
begin == 0 ? 0 : parts[begin - 1].size);
}
}
}