[OSM-dev] Rantings about API 0.6

Stefan de Konink stefan at konink.de
Wed Feb 11 14:25:19 GMT 2009


Iván Sánchez Ortega wrote:
> El Miércoles, 11 de Febrero de 2009, Stefan de Konink escribió:
>>> I'm not a foreign keys guru myself but I think it may be difficult to
>>> have one with the relation_members as designed currently.
>> I have solved that by splitting the members in 3 distinct tables; but
>> placed an explicit index so I can always retrieve the members in the
>> order they were inserted.
> 
> It can also be solved by nuking the "member_type" and "member_id" columns, and 
> putting three new columns: "member_node_id", "member_way_id" 
> and "member_relation_id", all allowing NULL, with a foreign key to the 
> corresponding table, and with a cute custom constraint or even a view to make 
> sure two of these three columns are kept NULL.

I prefer not to go to the unnormalised way ;) And NULL on constraints 
are evil ;)


Stefan




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