query_cache_size0, the default before MariaDB 10.1.7,
                effectively
                disables the query cache.
            Warning: Starting from MariaDB 10.1.7, query_cache_type is automatically set to ON if the server is started with the query_cache_size set to a non-zero (and non-default) value. This will happen even if query_cache_type is explicitly set to OFF in the configuration.
--query-cache-size=#
            numeric
            1M (>= MariaDB
                    10.1.7), 0 (<= MariaDB 10.1.6)
                (although frequently given a default value in some setups)
            0 upwards in units of 1024.