[Bug] Union read policy will never take effects in block reader

[Hastyshell]

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• I had searched in the issues and found no similar issues.

Version

Sine 2.0.

What's Wrong?

BlockReader::_rowsets_overlapping always return true even if non-overlap, resulting in union read optimization never takes effect.

bool BlockReader::_rowsets_overlapping(const ReaderParams& read_params) {
    std::string cur_max_key;
    const std::vector<RowSetSplits>& rs_splits = read_params.rs_splits;
    for (const auto& rs_split : rs_splits) {
        // version 0-1 of every tablet is empty, just skip this rowset
        if (rs_split.rs_reader->rowset()->version().second == 1) {
            continue;
        }
        if (rs_split.rs_reader->rowset()->num_rows() == 0) {
            continue;
        }
        if (rs_split.rs_reader->rowset()->is_segments_overlapping()) {
            return true;
        }
        std::string min_key;
        bool has_min_key = rs_split.rs_reader->rowset()->min_key(&min_key);
        if (!has_min_key) {
            return true;
        }
        if (min_key <= cur_max_key) {
            return true;
        }
        CHECK(rs_split.rs_reader->rowset()->max_key(&cur_max_key));
    }

    for (const auto& rs_reader : rs_splits) {
        // version 0-1 of every tablet is empty, just skip this rowset
        if (rs_reader.rs_reader->rowset()->version().second == 1) {
            continue;
        }
        if (rs_reader.rs_reader->rowset()->num_rows() == 0) {
            continue;
        }
        if (rs_reader.rs_reader->rowset()->is_segments_overlapping()) {
            return true;
        }
        std::string min_key;
        bool has_min_key = rs_reader.rs_reader->rowset()->min_key(&min_key);
        if (!has_min_key) {
            return true;
        }
        if (min_key <= cur_max_key) {
            return true;
        }
        CHECK(rs_reader.rs_reader->rowset()->max_key(&cur_max_key));
    }
    return false;
}

What You Expected?

Make it correct.

How to Reproduce?

Doing compaction without vertical policy, or query a dataset with progressive increasing keys.

Anything Else?

Not a correctness problem, may gain performance if make it correct (but not for vertical block reader).

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct