Archetype relational mapping - a practical openEHR persistence solution

Bert Verhees bert.verhees at rosa.nl
Tue Feb 16 11:06:32 EST 2016


If a database has a field-type XML, then I expect it does something 
special with that field that justifies the fieldtypename.
Especially I expect that from Postgres, because they mostly do good things.

Bert

On 16-02-16 11:47, Thomas Beale wrote:
>
>
> On 14/02/2016 23:25, Bert Verhees wrote:
>>
>> One doesn't know what software really does. One must distinguish what 
>> software seems to do and what it really does.
>>
>> Storing XML really as XML means, storing a lot of redundant 
>> information. I don't know, but I cannot believe postgress really 
>> stores the full tag names,  even when they occur thousand times. I 
>> would be really disappointed if they do.
>>
>> Bert
>>
>
> storing a text serialisation of an object structure in a database 
> never makes sense when you think about it. Storing a /binary/ 
> serialisation is a normal 'blob' approach, and if you are not doing 
> blobs or partial blobs, then you are doing transparent representation, 
> in which case things like XML or JSON don't come into it - they only 
> make sense as one kind of generated view on data.
>
> You might implement blobs using a zipped text format, but in a serious 
> scalable implementation that would surely have to be the least 
> efficient of viable approaches.
>
> I can't think of any circumstance where a DB would actually store its 
> information as XML instance text (other than where some column value 
> happened to be an XMLstring, i.e. the XML is just data).
>
> - thomas
>
>
> _______________________________________________
> openEHR-technical mailing list
> openEHR-technical at lists.openehr.org
> http://lists.openehr.org/mailman/listinfo/openehr-technical_lists.openehr.org

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openehr.org/pipermail/openehr-technical_lists.openehr.org/attachments/20160216/4b345782/attachment-0002.html>


More information about the openEHR-technical mailing list