Method IStorageURLBase

src/Storages/StorageURL.cpp:143–228

}

IStorageURLBase::IStorageURLBase(
    const String & uri_,
    const ContextPtr & context_,
    const StorageID & table_id_,
    const String & format_name_,
    const std::optional<FormatSettings> & format_settings_,
    const ColumnsDescription & columns_,
    const ConstraintsDescription & constraints_,
    const String & comment,
    const String & compression_method_,
    const HTTPHeaderEntries & headers_,
    const String & http_method_,
    ASTPtr partition_by_,
    bool distributed_processing_)
    : IStorage(table_id_)
    , uri(uri_)
    , compression_method(chooseCompressionMethod(Poco::URI(uri_).getPath(), compression_method_))
    , format_name(format_name_)
    , format_settings(format_settings_)
    , headers(headers_)
    , http_method(http_method_)
    , partition_by(partition_by_)
    , distributed_processing(distributed_processing_)
{
    if (format_name != "auto")
        FormatFactory::instance().checkFormatName(format_name);

    StorageInMemoryMetadata storage_metadata;

    if (columns_.empty())
    {
        ColumnsDescription columns;
        if (format_name == "auto")
            std::tie(columns, format_name) = getTableStructureAndFormatFromData(uri, compression_method, headers, format_settings, context_);
        else
            columns = getTableStructureFromData(format_name, uri, compression_method, headers, format_settings, context_);

        storage_metadata.setColumns(columns);
    }
    else
    {
        if (format_name == "auto")
            format_name = getTableStructureAndFormatFromData(uri, compression_method, headers, format_settings, context_).second;

        /// We don't allow special columns in URL storage.
        if (!columns_.hasOnlyOrdinary())
            throw Exception(ErrorCodes::BAD_ARGUMENTS, "Table engine URL doesn't support special columns like MATERIALIZED, ALIAS or EPHEMERAL");
        storage_metadata.setColumns(columns_);
    }

    supports_prewhere = FormatFactory::instance().checkIfFormatSupportsPrewhere(format_name, context_, format_settings);

    storage_metadata.setConstraints(constraints_);
    storage_metadata.setComment(comment);

    auto & storage_columns = storage_metadata.columns;

    const auto sample_path = getSampleURI(uri, context_);