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MergeSelector: further [#METR-21840].

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This commit is contained in:
Alexey Milovidov 2016-11-01 23:30:40 +03:00
parent aaec9d1db6
commit 22719b1114
1 changed files with 19 additions and 39 deletions
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58
dbms/src/Storages/MergeTree/SimpleMergeSelector.cpp
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@ -78,62 +78,42 @@ void selectWithinPartition(
Estimator & estimator,
const SimpleMergeSelector::Settings & settings)
{
if (parts.size() <= 1)
size_t parts_count = parts.size();
if (parts_count <= 1)
return;
size_t parts_count = parts.size();
size_t prefix_sum = 0;
std::vector<size_t> prefix_sums(parts.size() + 1);
double actual_base = settings.base;
for (size_t i = 0; i < parts_count; ++i)
{
prefix_sum += parts[i].size;
prefix_sums[i + 1] = prefix_sum;
}
Estimator local_estimator;
if (parts_count > settings.lower_base_after_num_parts
|| current_min_part_age > settings.lower_base_after_seconds)
actual_base = 1;
for (size_t begin = 0; begin < parts_count; ++begin)
{
size_t sum_size = parts[begin].size;
size_t max_size = parts[begin].size;
for (size_t end = begin + 2; end <= parts_count; ++end)
{
if (settings.max_parts_to_merge_at_once && end - begin > settings.max_parts_to_merge_at_once)
break;
size_t sum_size = prefix_sums[end] - prefix_sums[begin];
sum_size += parts[end - 1].size;
if (parts[end - 1].size > max_size)
max_size = parts[end - 1].size;
if (max_total_size_to_merge && sum_size > max_total_size_to_merge)
break;
local_estimator.consider(
parts.begin() + begin,
parts.begin() + end,
sum_size,
begin == 0 ? 0 : parts[begin - 1].size,
end == parts_count ? 0 : parts[end].size);
if (static_cast<double>(sum_size) / max_size >= actual_base)
estimator.consider(
parts.begin() + begin,
parts.begin() + end,
sum_size,
begin == 0 ? 0 : parts[begin - 1].size,
end == parts_count ? 0 : parts[end].size);
}
}
double actual_base = settings.base;
if (parts.size() > settings.lower_base_after_num_parts
|| current_min_part_age > settings.lower_base_after_seconds)
actual_base = 1;
{
size_t sum_size = 0;
size_t max_size = 0;
for (auto it = local_estimator.best_begin; it != local_estimator.best_end; ++it)
{
sum_size += it->size;
if (it->size > max_size)
max_size = it->size;
}
if (static_cast<double>(sum_size) / max_size >= actual_base)
estimator.consider(local_estimator.best_begin, local_estimator.best_end, sum_size, 0, 0);
}
}
}