Method execute

src/Interpreters/ArrayJoinAction.cpp:119–216

}

void ArrayJoinAction::execute(Block & block)
{
    if (columns.empty())
        throw Exception("No arrays to join", ErrorCodes::LOGICAL_ERROR);

    ColumnPtr any_array_map_ptr = block.getByName(*columns.begin()).column->convertToFullColumnIfConst();
    const auto * any_array = getArrayJoinColumnRawPtr(any_array_map_ptr);
    if (!any_array)
        throw Exception("ARRAY JOIN of not array: " + *columns.begin(), ErrorCodes::TYPE_MISMATCH);

    /// If LEFT ARRAY JOIN, then we create columns in which empty arrays are replaced by arrays with one element - the default value.
    std::map<String, ColumnPtr> non_empty_array_columns;

    if (is_unaligned)
    {
        /// Resize all array joined columns to the longest one, (at least 1 if LEFT ARRAY JOIN), padded with default values.
        auto rows = block.rows();
        auto uint64 = std::make_shared<DataTypeUInt64>();
        ColumnWithTypeAndName column_of_max_length{{}, uint64, {}};
        if (is_left)
            column_of_max_length = ColumnWithTypeAndName(uint64->createColumnConst(rows, 1u), uint64, {});
        else
            column_of_max_length = ColumnWithTypeAndName(uint64->createColumnConst(rows, 0u), uint64, {});

        for (const auto & name : columns)
        {
            auto & src_col = block.getByName(name);

            ColumnsWithTypeAndName tmp_block{convertArrayJoinColumn(src_col)};
            auto len_col = function_length->build(tmp_block)->execute(tmp_block, uint64, rows);

            ColumnsWithTypeAndName tmp_block2{column_of_max_length, {len_col, uint64, {}}};
            column_of_max_length.column = function_greatest->build(tmp_block2)->execute(tmp_block2, uint64, rows);
        }

        for (const auto & name : columns)
        {
            auto & src_col = block.getByName(name);

            ColumnWithTypeAndName array_col = convertArrayJoinColumn(src_col);
            ColumnsWithTypeAndName tmp_block{array_col, column_of_max_length};
            array_col.column = function_array_resize->build(tmp_block)->execute(tmp_block, array_col.type, rows);

            src_col = std::move(array_col);
            any_array_map_ptr = src_col.column->convertToFullColumnIfConst();
        }

        any_array = getArrayJoinColumnRawPtr(any_array_map_ptr);
        if (!any_array)
            throw Exception(ErrorCodes::TYPE_MISMATCH, "ARRAY JOIN requires array or map argument");
    }
    else if (is_left)
    {
        for (const auto & name : columns)
        {
            auto src_col = block.getByName(name);
            ColumnWithTypeAndName array_col = convertArrayJoinColumn(src_col);
            ColumnsWithTypeAndName tmp_block{array_col};