ClickHouse/src/Storages/MergeTree/PartitionPruner.cpp

#include <Storages/MergeTree/PartitionPruner.h>

namespace DB
{

bool PartitionPruner::canBePruned(const DataPart & part)
{
    if (part.isEmpty())
        return true;
    const auto & partition_id = part.info.partition_id;
    bool is_valid;
    if (auto it = partition_filter_map.find(partition_id); it != partition_filter_map.end())
        is_valid = it->second;
    else
    {
        const auto & partition_value = part.partition.value;
        std::vector<FieldRef> index_value(partition_value.begin(), partition_value.end());
        for (auto & field : index_value)
        {
            // NULL_LAST
            if (field.isNull())
                field = POSITIVE_INFINITY;
        }
        is_valid = partition_condition.mayBeTrueInRange(
            partition_value.size(), index_value.data(), index_value.data(), partition_key.data_types);
        partition_filter_map.emplace(partition_id, is_valid);
        if (!is_valid)
        {
            WriteBufferFromOwnString buf;
            part.partition.serializeText(part.storage, buf, FormatSettings{});
            LOG_TRACE(&Poco::Logger::get("PartitionPruner"), "Partition {} gets pruned", buf.str());
        }
    }
    return !is_valid;
}

}