**Use case**

If FixedString is used with more than 256 bytes in size, it is suspicious and most likely indicates misusage.
Forbid this by default and add a setting to override it; ATTACH queries should allow creating tables nevertheless.

See also: `allow_suspicious_low_cardinality_types`.

}
    if (create.storage->engine->name == "MaterializedPostgreSQL"
        && !getContext()->getSettingsRef().allow_experimental_database_materialized_postgresql
        && !internal)
    {
        throw Exception("MaterializedPostgreSQL is an experimental database engine. "
                        "Enable allow_experimental_database_materialized_postgresql to use it.", ErrorCodes::UNKNOWN_DATABASE_ENGINE);
    }
    bool need_write_metadata = !create.attach || !fs::exists(metadata_file_path);
    bool need_lock_uuid = internal || need_write_metadata;
    auto mode = getLoadingStrictnessLevel(create.attach, force_attach, has_force_restore_data_flag);
    
    
    TemporaryLockForUUIDDirectory uuid_lock;
    if (need_lock_uuid)
        uuid_lock = TemporaryLockForUUIDDirectory{create.uuid};
    else if (create.uuid != UUIDHelpers::Nil && !DatabaseCatalog::instance().hasUUIDMapping(create.uuid))
        throw Exception(ErrorCodes::LOGICAL_ERROR, "Cannot find UUID mapping for {}, it's a bug", create.uuid);
    DatabasePtr database = DatabaseFactory::get(create, metadata_path / "", getContext());
    if (create.uuid != UUIDHelpers::Nil)
        create.setDatabase(TABLE_WITH_UUID_NAME_PLACEHOLDER);
    if (need_write_metadata)
    {
        create.attach = true;
        create.if_not_exists = false;
        WriteBufferFromOwnString statement_buf;
        formatAST(create, statement_buf, false);
        writeChar('\n', statement_buf);
        String statement = statement_buf.str();