More Comments on the Direct Mapping Specification

Hi all,

recently, i read the Direct Mapping document (Sören asked me & and am 
interested in the topic). Some points were already mentioned before & 
most of the spec is clear (to me) i still have a few comments and 
suggestions i want to share with you.

Cheers, Jörg

General remarks:
* The term "direct mapping" is used frequently as a term, why not write 
it as Direct Mapping (with capital letters).

* Headlines: Capitalization in headlines is not always consistent.


* I got what direct mapping is all about (i hope at least so), when i 
went through chapter 2, cause is somehow missed out that direct mapping, 
is a mapping that doesn't need a mapping configuration, it just 
translates a SQL db directly into an RDF graph.

I suggest to write more explicitly, in a simple and non-formal way what 
is specific to direct mapping, what is the scope of direct mapping
and what are its limitations, perhaps like that:

This document describes direct mapping, a transformation of a relational 
database into an RDF Graph, that only takes the relational database as 
input. Direct mapping does not require additional configuration.

Direct Mapping translates the SQL schema into an RDF vocabulary, which 
is used to describe the RDF instances created out of the database 
records. More refined transformation processes may provide custom 
mapping options, for example to reuse existing vocabularies.

As direct mapping solely relies on the SQL schema definition, relations 
that are not defined in the schema, are therefore not considered.

This would help to make it for the practical guys more clear what this 
document is all about.

Further Questions/Remarks:


I find the pencil-prefix a bit odd, as it will be solely used by one 


* The function [35] is a not mentioned in the text (it is url encode) 
maybe because of the todo in Chapter 3?
* Definition of φ [36] is not defined here as a function, is it?

Some sentences that *could* be remodeled (no warranty, non-native speaker):

* proliferate -> doesn't that have a negative connotation
* abound -> use as verb? is correct, but sentence seems a bit odd to me.

* Following is SQL to create a simple example .... -> The following SQL 
represents a simple example
* HTML tables will be used .... to convey SQL tables -> Sample data from 
SQL tables will be displayed in HTML tables
* In this expression, each row... -> in this example, each row of the 
aforementioned tables produces a set of triples....

* In this chapter, "Foreign keys referencing candidate keys", claims 
that complex schemas  have composite primary keys. The samples but have 
composite foreign keys.
* Per the People tables's  -> Per (??) the Peoples table's

* The text in brackets: I don't understand, why that text is here, the 
SQL schema is already defined ;-)

Received on Wednesday, 17 August 2011 15:08:21 UTC