Data integrity =============== Data integrity refers to the fact that data must be reliable and accurate throughout its lifecycle. This means that the value must be: - of high quality - appropriate to the overall context Isolated variable ----------------- Data quality ~~~~~~~~~~~~ The values of the variables must be individually of good quality. .. toctree:: :titlesonly: typing variable_validation Access control ~~~~~~~~~~~~~~ .. toctree:: :titlesonly: mode variable_properties Overall coherence ----------------- An isolated variable can be considered to be of quality but become inconsistent depending on the context. .. index:: consistency Consistency ~~~~~~~~~~~ For example, if a minimum value and then a maximum value are requested, the minimum must be lesser than the maximum. Overall consistency is initially managed by personalized validators which will validate the value of a variable in relation to others. Context access control ~~~~~~~~~~~~~~~~~~~~~~ Access control occurs as soon as an attempt is made to access a variable. Remember, we talked about the :ref:`hidden variable ` and :ref:`disabled variable ` variables. These properties become fully meaningful when managing overall consistency. Why ask for the domain name of a service if we haven't activated that service just before?