Re: ISSUE-34, tableName

On Wed, Jul 13, 2011 at 8:40 AM, Michael Hausenblas <
michael.hausenblas@deri.org> wrote:

>  [[
>> PROPOSAL: To resolve ISSUE-34, drop rr:tableOwner, and instead state that
>> rr:tableName MAY be qualified to include a schema name and a catalog name
>> ]]
>>
>
> +1
>
>
+1


> Cheers,
>        Michael
> --
> Dr. Michael Hausenblas, Research Fellow
> LiDRC - Linked Data Research Centre
> DERI - Digital Enterprise Research Institute
> NUIG - National University of Ireland, Galway
> Ireland, Europe
> Tel. +353 91 495730
> http://linkeddata.deri.ie/
> http://sw-app.org/about.html
>
>
> On 12 Jul 2011, at 19:26, Richard Cyganiak wrote:
>
>  All,
>>
>> Continuing the discussion from the call.
>>
>> First, please review what the spec currently says:
>> http://www.w3.org/2001/sw/**rdb2rdf/r2rml/#physical-tables<http://www.w3.org/2001/sw/rdb2rdf/r2rml/#physical-tables>
>>
>> I'll explain the proposal in a bit more detail, for the sake of clarity.
>> The proposal is to drop rr:tableOwner, and instead state that a "table or
>> view name" MAY be qualified to include a schema name and a catalog name.
>>
>> The intention is that all of the following are all valid values for
>> rr:tableName:
>>
>>  emp
>>  EMP
>>  SCOTT.EMP
>>  CAT.SCOTT.EMP
>>  "Emp"
>>  "Scott Smith".EMP
>>  SCOTT."!@#$%^&"
>>
>> If catalog or schema are absent, then the defaults of the SQL connection
>> are used. (Note that's nothing new; rr:tableOwner was always optional.)
>>
>> My arguments against other proposed designs are as follows:
>>
>> Proposal: no change
>> Objection: rr:tableOwner is nonstandard terminology and the standard term
>> is schema.
>>
>> Proposal: just rename rr:tableOwner to rr:tableSchema
>> Objection: A fully qualified table name is [[Catalog.]Schema.]Table, and
>> there is no case for separating [Catalog.]Schema from Table
>>
>> Proposal: have three properties rr:tableName, rr:schemaName,
>> rr:catalogName (or similar names)
>> Objection: This works and is consistent. But it puts undue burden on users
>> who now have to use three properties for what can be achieved with one.
>> Users already can write fully qualified table names in catalog.schema.table
>> notation in rr:sqlQuery, so why should rr:tableName work any differently?
>>
>> Proposal: add rr:fullyQualifiedTableName as an alternative to the current
>> design
>> Objection: Having two different ways of doing exactly the same thing
>> creates extra cognitive load for mapping authors, extra work for
>> implementers, and extra work for editors, with no benefit.
>>
>> Proposal: allow fully qualified names, but call the property rr:objectName
>> or similar to make clear it's something different from an unqualified table
>> name
>> Objection: The SQL spec states that a table name may include schema and
>> catalog, so calling it rr:tableName is consistent.
>>
>> Objection: tableName is not intuitive because it doesn't mention views
>> Counter: The SQL spec says that views are identified by table names. One
>> can use a view almost everywhere in SQL where a table is allowed; and this
>> fact is usually simply assumed and not explicitly pointed out by always
>> referring to "table or view". The R2RML spec very explicitly states, in
>> multiple places, that views are allowed too.
>>
>> Objection: Parsing fully qualified table names places undue burden on
>> implementers
>> Counter: It's not hard.
>> Regex for an undelimited identifier: [^.]+
>> Regex for a delimited identifier: ("[^"]*")+
>> Regex for an identifier: (delimited|undelimited)
>> Regex for a qualified table name: ((identifier\.)?identifier\.)?**
>> identifier
>> (This regex is just for matching and splitting the three parts; it doesn't
>> validate the characters that are allowed in undelimited identifiers. That's
>> orthogonal to ISSUE-34.)
>>
>> So my proposal is still:
>>
>> [[
>> PROPOSAL: To resolve ISSUE-34, drop rr:tableOwner, and instead state that
>> rr:tableName MAY be qualified to include a schema name and a catalog name
>> ]]
>>
>
>
>