Reloading .xds files from an old rulebase

Question

I want to deploy interviews and allow users to save sessions to be reloaded later, possibly after the rulebase has been updated.
If the .xds file contains a rulebase attribute that does not exist in the new rulebase, the .xds file will not reload. Is this correct?
If this is indeed a problem, it is compounded by the fact that when OPA creates the .xds file from the interview data, it does not merely include attributes that the user answered. It sometimes includes a host of other attributes, some of which are not even base-level. The more attributes in the .xds file, the greater the risk that one of them is not in the new version of the rulebase.
This is an extremely brittle state of affairs.
What is the official recommendation about how to handle this?

Answer 1

user12993351 wrote:
If the .xds file contains a rulebase attribute that does not exist in the new rulebase, the .xds file will not reload. Is this correct?Yes that is correct.
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If this is indeed a problem, it is compounded by the fact that when OPA creates the .xds file from the interview data, it does not merely include attributes that the user answered. It sometimes includes a host of other attributes, some of which are not even base-level. The more attributes in the .xds file, the greater the risk that one of them is not in the new version of the rulebase.This shouldn't be the case. The XDS file generated by the default data adaptor in Web Determinations should only save out user set data. If you are seeing this behaviour, please feel free to e-mail me (kristy[dot]vandervlist[at]oracle[dot]com) a sample rulebase project and xds file and we'll take a closer look.
What is the official recommendation about how to handle this?How this issue gets handled is really going to depend on the specific circumstances of the project itself. The danger in changing the current behaviour of the xds data adaptor to ignore values for attributes, entities and/or relationships that no longer exist and continue to load the xds file is that you may inadvertently end up silently losing data and so therefore we erred on the side of caution and refuse to load the file. That being said, we are currently looking at modifying the existing behaviour in future releases.
Regardless, as a general rule we do not recommend using the default xds data adaptor that comes Web Determinations in a production environment as it is generally desirable to have a more robust form of data storage (eg a database) as opposed to xml saved in a file. Implementing a data adaptor will allow you to integrate with your data source of choice as well as give you complete control over how the data is loaded, including what to do in the circumstances you describe.
Thanks,
Kristy