wgtmac commented on code in PR #42133: URL: https://github.com/apache/arrow/pull/42133#discussion_r1639146626
########## cpp/src/arrow/array/statistics.h: ########## @@ -0,0 +1,84 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +#pragma once + +#include <optional> +#include <variant> + +#include "arrow/util/visibility.h" + +namespace arrow { + +/// \brief Statistics for an Array +/// +/// Apache Arrow format doesn't have statistics but data source such +/// as Apache Parquet may have statistics. Statistics associate with +/// data source can be read unified API via this class. +struct ARROW_EXPORT ArrayStatistics { + public: + using ElementBufferType = std::variant<bool, int8_t, uint8_t, int16_t, uint16_t, + int32_t, uint32_t, int64_t, uint64_t>; + + ArrayStatistics() = default; + ~ArrayStatistics() = default; + + /// \brief The number of null values, may not be set + std::optional<int64_t> null_count = std::nullopt; + + /// \brief The number of distinct values, may not be set + std::optional<int64_t> distinct_count = std::nullopt; + + /// \brief The current minimum value buffer, may not be set + std::optional<ElementBufferType> min_buffer = std::nullopt; Review Comment: `is_max_value_exact` and `is_min_value_exact` are added recently and we are not using them at least in parquet-cpp and parquet-java. FYI. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
