ISSUE-71 (child-parent-collision): Column name collisions between child and parent queries in RefObjectMaps [R2RML]

ISSUE-71 (child-parent-collision): Column name collisions between child and parent queries in RefObjectMaps [R2RML]

http://www.w3.org/2001/sw/rdb2rdf/track/issues/71

Raised by: Richard Cyganiak
On product: R2RML

This is part of David's Last Call comments:
http://lists.w3.org/Archives/Public/public-rdb2rdf-comments/2011Oct/0022.html

R2RML Section 8 states:

[[
SELECT * FROM ({child-query}) AS child, ({parent-query}) AS parent
]]

>From a SQL perspective, this feels wrong because it doesn't address the issue of column name collisions between the child and parent query.

Is the thought that we can just ignore this because we describe in section 11 that the projected columns are split between child and parent?

This seems to be not fully thought through. I think either the spec needs something that states that the sets of columns are disjoint (but that would limit the usefulness), or the mechanics in sections 8 and 11 need to be changed.

Received on Monday, 7 November 2011 16:17:47 UTC