15:46:03 <RRSAgent> RRSAgent has joined #RDB2RDF
15:46:03 <RRSAgent> logging to http://www.w3.org/2012/05/01-RDB2RDF-irc
15:46:05 <trackbot> RRSAgent, make logs world
15:46:05 <Zakim> Zakim has joined #RDB2RDF
15:46:07 <trackbot> Zakim, this will be 7322733
15:46:07 <Zakim> ok, trackbot; I see SW_RDB2RDF()12:00PM scheduled to start in 14 minutes
15:46:08 <trackbot> Meeting: RDB2RDF Working Group Teleconference
15:46:08 <trackbot> Date: 01 May 2012
15:46:22 <mhausenblas> Agenda: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2012May/0001.html
15:46:59 <mhausenblas> Chair: Michael
15:47:08 <mhausenblas> regrets+ Joerg
15:47:14 <mhausenblas> present+ Michael
15:47:22 <mhausenblas> RRSAgent, draft minutes
15:47:22 <RRSAgent> I have made the request to generate http://www.w3.org/2012/05/01-RDB2RDF-minutes.html mhausenblas
15:47:33 <mhausenblas> RRSAgent, make logs public
15:55:44 <Ashok> Ashok has joined #rdb2rdf
15:57:58 <Ashok> Sure!
15:58:07 <mhausenblas> Thanks!
15:58:13 <mhausenblas> scribenick: Ashok 
15:59:05 <Ashok> zakim, code?
15:59:05 <Zakim> the conference code is 7322733 (tel:+1.617.761.6200 sip:zakim@voip.w3.org), Ashok
15:59:18 <Zakim> SW_RDB2RDF()12:00PM has now started
15:59:25 <Zakim> +Ashok_Malhotra
15:59:29 <Zakim> +mhausenblas
15:59:41 <mhausenblas> present+ Ashok
16:00:27 <ivan> ivan has joined #rdb2rdf
16:00:49 <Zakim> +OpenLink_Software
16:00:54 <cygri> zakim, i'm with mhausenblas 
16:00:54 <Zakim> +cygri; got it
16:00:58 <mhausenblas> present+ Ted
16:01:01 <MacTed> Zakim, OpenLink_Software is temporarily me
16:01:01 <Zakim> +MacTed; got it
16:01:02 <dmcneil> dmcneil has joined #RDB2RDF
16:01:05 <MacTed> Zakim, mute me
16:01:05 <Zakim> MacTed should now be muted
16:01:06 <mhausenblas> present+ Richard
16:01:29 <mhausenblas> RRSAgent, draft minutes
16:01:29 <RRSAgent> I have made the request to generate http://www.w3.org/2012/05/01-RDB2RDF-minutes.html mhausenblas
16:01:29 <Zakim> +dmcneil
16:01:38 <mhausenblas> present+ David
16:01:52 <ivan> zakim, dial ivan-voip
16:01:52 <Zakim> ok, ivan; the call is being made
16:01:54 <Zakim> +Ivan
16:02:02 <cygri> zakim, nuno is with mhausenblas 
16:02:02 <Zakim> +nuno; got it
16:02:10 <Zakim> -Ivan
16:02:19 <mhausenblas> present+ Nuno
16:02:23 <nunolopes> nunolopes has joined #rdb2rdf
16:02:31 <cygri> zakim, nunolopes is with mhausenblas 
16:02:31 <Zakim> +nunolopes; got it
16:02:53 <Souri> Souri has joined #rdb2rdf
16:03:23 <Zakim> +Souri
16:03:32 <mhausenblas> present+ Souri
16:03:46 <juansequeda> juansequeda has joined #rdb2rdf
16:03:54 <Seema> Seema has joined #rdb2rdf
16:04:22 <Zakim> +juansequeda
16:04:28 <mhausenblas> present+ Juan
16:05:29 <Ashok> Topic:  Minutes of Last Meeting
16:05:32 <Ashok> ROPOSAL: Accept the minutes of last meeting http://www.w3.org/2012/04/24-RDB2RDF-minutes.html
16:05:50 <mhausenblas> s/ROPOSAL/PROPOSAL
16:05:53 <cygri> +1
16:06:13 <Ashok> Minutes acceptes without objection
16:06:21 <mhausenblas> Topic:  Fixing an omission in R2RML: syntax of blank node labels
16:06:51 <mhausenblas> RRSAgent, draft minutes
16:06:51 <RRSAgent> I have made the request to generate http://www.w3.org/2012/05/01-RDB2RDF-minutes.html mhausenblas
16:06:59 <ivan> zakim, dial ivan-home
16:06:59 <Zakim> ok, ivan; the call is being made
16:07:01 <Zakim> +Ivan
16:07:57 <Zakim> +seema
16:08:05 <mhausenblas> present+ Seema
16:08:11 <mhausenblas> PROPOSAL: Change Section 11.2 of R2RML http://www.w3.org/TR/2012/CR-r2rml-20120223/#generated-rdf-term) from:
16:08:12 <mhausenblas> [[
16:08:13 <mhausenblas> If the term type is rr:BlankNode: Return a blank node whose blank node identifier is the natural RDF lexical form corresponding to value.
16:08:15 <mhausenblas> ]]
16:08:16 <mhausenblas> to:
16:08:18 <mhausenblas> [[
16:08:19 <mhausenblas> If the term type is rr:BlankNode: Return a blank node that is unique to the natural RDF lexical form corresponding to value.
16:08:20 <mhausenblas> NOTE: RDF syntaxes and RDF APIs generally represent blank nodes with blank node identifiers. But the characters allowed in blank node identifiers differ between syntaxes, and not all characters occurring in value may be allowed, so a bijective mapping function from values to valid blank node identifiers may be required. The details of this mapping function are implementation-dependent, and an R2RML processors may have to use different functions for 
16:08:23 <mhausenblas> different output syntaxes or access interfaces. Strings matching the regular expression [a-zA-Z_][a-zA-Z_0-9-]* are valid blank node identifiers in all W3C-recommended RDF syntaxes.
16:08:26 <mhausenblas> ]]
16:08:42 <dmcneil> +q
16:08:52 <mhausenblas> ack dmcneil 
16:08:59 <Ashok> q+
16:09:03 <mhausenblas> q?
16:09:25 <Ashok> Topic: Fixing an omission in R2RML: syntax of blank node labels
16:10:37 <mhausenblas> present+ Ivan
16:12:30 <mhausenblas> ack Ashok 
16:14:55 <mhausenblas> q?
16:14:56 <MacTed> +1
16:14:58 <Ashok> RESOLUTION: Proposal accepted without change
16:15:01 <ivan> 1
16:15:18 <mhausenblas> Topic:  Using non-existing column in mapping 
16:15:33 <Ashok> Topic: Using non-existing column in mapping   http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2012Apr/0018.html
16:15:36 <mhausenblas> Section 6 of the R2RML spec (http://www.w3.org/TR/2012/CR-r2rml-20120223/#triples-map) states:
16:15:36 <mhausenblas> [[
16:15:38 <mhausenblas> The referenced columns of all term maps of a triples map (subject map, predicate maps, object maps, graph maps) MUST be column names that exist in the term map's logical table.
16:15:39 <mhausenblas> ]]
16:15:41 <mhausenblas> PROPOSAL: Any referenced columns (that is, the columns mentioned in rr:column, rr:template, etc.) that don't exist in the rr:sqlQuery or table are treated simply as being NULL, rather than being considered an error. Perhaps the case could still be treated as a warning:
16:15:42 <mhausenblas> [[
16:15:43 <mhausenblas> Processors MAY warn mapping authors if a referenced column does not exist in the logical table.
16:15:44 <mhausenblas> ]]
16:16:57 <MacTed> I'd prefer SHOULD to MAY
16:17:27 <juansequeda> +1 to MacTed's comment
16:17:38 <Souri> -1 (prefer error over warning -- returning wrong value from a query could be disastrous)
16:18:15 <MacTed> SHOULD warn, MAY error?
16:19:11 <mhausenblas> PROPOSAL: Any referenced columns (that is, the columns mentioned in rr:column, rr:template, etc.) that don't exist in the rr:sqlQuery or table are treated simply as being NULL, rather than being considered a warning. Processors SHOULD warn mapping authors if a referenced column does not exist in the logical table.
16:20:12 <MacTed> Zakim, unmute me
16:20:12 <Zakim> MacTed should no longer be muted
16:21:04 <MacTed> PROPOSAL: Any referenced columns (that is, the columns mentioned in rr:column, rr:template, etc.) that don't exist in the rr:sqlQuery or table are treated simply as being NULL, rather than being considered a warning. Processors SHOULD error, MAY warn mapping authors if a referenced column does not exist in the logical table.
16:23:15 <mhausenblas> q?
16:23:37 <dmcneil> +q
16:24:41 <MacTed> PROPOSAL: Processors SHOULD error if any referenced columns (that is, the columns mentioned in rr:column, rr:template, etc.) don't exist in the rr:sqlQuery or table. Processors MAY treat such as NULL but if so, SHOULD return a warning to mapping authors.
16:25:17 <mhausenblas> q?
16:25:33 <mhausenblas> ack dmcneil
16:26:11 <Zakim> +EricP
16:26:21 <Souri> +1 to David's comment
16:26:22 <mhausenblas> present+ Eric
16:26:42 <Ashok> s/such/such columns/
16:29:53 <cygri> Ashok++
16:30:32 <Souri> What exactly was the earlier statement about it?
16:30:45 <juansequeda> Can't we just choose one?
16:31:16 <juansequeda> PROPOSAL: Processors MUST error if any referenced columns (that is, the columns mentioned in rr:column, rr:template, etc.) don't exist in the rr:sqlQuery or table.
16:31:29 <Souri> +0 from me (as long as earlier statement said "error" is the norm)
16:31:59 <Ashok> WG decided not to change the spec in this regard
16:32:27 <Ashok> RESOLUTION: WG decided not to change the spec in this regard
16:32:36 <mhausenblas> Topic: Unnamed columns in rr:sqlQuery 
16:32:43 <mhausenblas> Section 5.2 of the R2RML spec (http://www.w3.org/TR/2012/CR-r2rml-20120223/#r2rml-views) states:
16:32:44 <mhausenblas> [[
16:32:45 <mhausenblas> Any columns in the SELECT list derived by projecting an expression MUST be named.
16:32:47 <mhausenblas> ]]
16:32:48 <mhausenblas> PROPOSAL: Above to be replaced with an informative note:
16:32:50 <mhausenblas> [[
16:32:51 <mhausenblas> Note: Any columns in the SELECT list derived by projecting an expression should be explicitly named because otherwise they cannot be referenced in the rest of the mapping.
16:32:51 <mhausenblas> ]]
16:33:09 <Ashok> Topic:  Unnamed columns in rr:sqlQuery   http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2012Apr/0017.html
16:33:12 <Souri> +1
16:33:26 <juansequeda> +1
16:33:42 <Souri> do we need to add "unique" ?
16:36:09 <Souri> Any columns in the SELECT list derived by projecting an expression MUS be explicitly named for those column names to be referenced in the rest of the mapping.
16:36:23 <Souri> s/ MUS / MUST /
16:36:24 <MacTed> PROPOSAL: Any columns in the SELECT list derived by projecting an expression SHOULD be named.
16:36:37 <Souri> q+
16:36:39 <ericP> what if you define the behavior in terms of a referenceable view?
16:36:44 <mhausenblas> q?
16:36:47 <ericP> (SQL:referenceable view)
16:36:47 <mhausenblas> ack Souri 
16:37:07 <ericP> that way the SQL spec defines it for you
16:38:04 <cygri> +1
16:38:05 <mhausenblas> q?
16:38:55 <Ashok> RESOLUTION:  Last proposal accepted by WG
16:39:49 <mhausenblas> Topic: XSD mapping for binary columns (xsd:hexBinary vs. xsd:base64Binary)
16:40:04 <mhausenblas> PROPOSAL: Binary datatypes like BLOB and VARBINARY should be mapped to xsd:hexBinary instead of xsd:base64Binary.
16:40:12 <MacTed> +1
16:40:16 <Ashok> Topic:  XSD mapping for binary columns (xsd:hexBinary vs. xsd:base64Binary)  http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2012Apr/0020.html
16:41:54 <ericP> +1
16:42:09 <ivan> ±0
16:42:26 <mhausenblas> Topic: Implementability for tables w/o primary key 
16:42:38 <Ashok> RESOLUTION:  Proposal accepted
16:42:44 <mhausenblas> PROPOSAL: In the DM spec, replace the following text:
16:42:45 <mhausenblas> [[
16:42:46 <mhausenblas> If the table has no primary key, the row node is a fresh blank node that is unique to this row.
16:42:48 <mhausenblas> ]]
16:42:49 <mhausenblas> with this:
16:42:51 <mhausenblas> [[
16:42:52 <mhausenblas> If the table has no primary key, the row node is a blank node. Distinct blank nodes MUST be generated for rows with distinct column values. For duplicate rows with identical values, implementations SHOULD generate a fresh blank for each duplicate row (resulting in a non-lean RDF graph [RDF Semantics]). However, if the underlying database system does not provide any means to reliably differentiate among the rows, then implementations MAY re-use the sa
16:42:53 <mhausenblas> blank node for multiple duplicate rows (resulting in a lean RDF graph). Implementations SHOULD document and advertise their chosen behavior.
16:42:55 <mhausenblas> ]]
16:43:28 <Ashok> PROPOSAL: Binary datatypes like BLOB and VARBINARY should be mapped to xsd:hexBinary instead of xsd:base64Binary.
16:43:44 <ericP> i think very few people are aware of lean graphs
16:43:47 <MacTed> s/PROPOSAL/RESOLVED/
16:43:51 <ericP> especially SPARQL users
16:43:51 <ivan> w+1 to Eric
16:43:58 <ivan> +1 to Eric
16:44:14 <ivan> I think it would just frighten people
16:44:26 <MacTed> +1 as written
16:46:05 <Ashok> Remove:  (resulting in a lean RDF graph)
16:46:38 <mhausenblas> PROPOSAL: If the table has no primary key, the row node is a blank node. Distinct blank nodes MUST be generated for rows with distinct column values. For duplicate rows with identical values, implementations SHOULD generate a fresh blank for each duplicate row. However, if the underlying database system does not provide any means to reliably differentiate among the rows, then implementations MAY re-use the same blank node for multiple duplicate rows.
16:46:39 <mhausenblas> Implementations SHOULD document and advertise their chosen behavior.
16:48:21 <cygri> ericP: http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2012Apr/0036.html
16:50:59 <MacTed> possible informative note -- "The result of reusing the same blank node for multiple rows is a lean RDF graph [RDF Semantics]; generating fresh blank nodes for each row results in a non-lean RDF graph. One significant implication of a lean RDF graph is loss of cardinality."
16:51:57 <juansequeda> PROPOSAL: If the table has no primary key, the row node is a blank node. Distinct blank nodes MUST be generated for rows with distinct column values. For duplicate rows with identical values, implementations SHOULD generate a fresh blank for each duplicate row. However, if the underlying database system does not provide any means to reliably differentiate among the rows, then implementations MAY re-use the same blank node for multiple duplicate rows w
16:51:57 <juansequeda> implies loss of cardinality
16:55:08 <Ashok> q+
16:55:15 <mhausenblas> q?
16:55:25 <mhausenblas> ack Ashok 
16:56:30 <juansequeda> My prediction:  most probably, implementors will not support SPARQL to SQL on the direct mapping on tables with no primary keys because 1) it's complicated to implement 2) corner case
16:58:47 <cygri> juansequeda++
17:02:11 <mhausenblas> regrets+ Marcelo
17:04:07 <ericP> D012-2tables2duplicates0nulls
17:05:36 <juansequeda> q+
17:05:40 <ivan> q+
17:05:43 <mhausenblas> q?
17:05:46 <mhausenblas> ack juansequeda 
17:06:44 <mhausenblas> ack ivan
17:06:51 <ivan> q+
17:07:01 <mhausenblas> ack ivan
17:07:39 <Ashok> Ivan:  Asks about our plans going forward
17:07:46 <cygri> q+
17:08:02 <mhausenblas> q?
17:08:12 <Ashok> Michael:  There are 2 open issues.  We need to resolve these.
17:08:40 <Ashok> Ivan:  So it looks like we are in second last call
17:09:13 <Ashok> Ivan:  Because of the moratorium we need to publish before next Thursday.
17:09:46 <Ashok> ... so we have some time pressure
17:10:23 <ivan> https://lists.w3.org/Archives/Member/chairs/2012AprJun/0043.html
17:11:00 <mhausenblas> regrets+ Boris
17:11:34 <mhausenblas> q?
17:11:37 <mhausenblas> ack cygri 
17:14:38 <Ashok> Richard:  The last 2 issues make the DM and R2RML mapping incompatible
17:15:14 <mhausenblas> http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2012Apr/0070.html
17:19:15 <Ashok> Topic:  DM cannot be implemented as an R2RML mapping (period encoding)  http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2012Apr/0021.html
17:19:29 <Ashok> RESOLUTION: re DM cannot be implemented as an R2RML mapping (period encoding) the WG agrees to go with http://lists.w3.org/Archives/Public/public-rdb2rdf-wg/2012Apr/0070.html
17:20:32 <mhausenblas> RRSAgent, draft minutes
17:20:32 <RRSAgent> I have made the request to generate http://www.w3.org/2012/05/01-RDB2RDF-minutes.html mhausenblas
17:20:56 <Ashok> rrsagent, make logs public
17:22:58 <cygri> ericP, how about tomorrow after the rdf-wg call?
17:23:18 <Ashok> Request Eric and Richard discuss over email or on the phone.  
17:23:51 <Ashok> We will resolve this issue on the My 8 call, one way or another.
17:23:52 <ivan> bye guys
17:23:55 <ivan> have fun:-)
17:24:03 <Zakim> -Ivan
17:24:04 <Ashok> ADJOURNED
17:24:23 <Zakim> -MacTed
17:25:59 <nunolopes> nunolopes has joined #rdb2rdf
17:26:08 <Zakim> -seema
17:26:24 <nunolopes> nunolopes has joined #rdb2rdf
17:30:10 <Zakim> -Souri
17:32:00 <ericP> SELECT * { ?I <IOUs#fname> ?fname ; <IOUs#amount> ?amount . ?L <Lives#fname> ?fname ; <Lives#city> ?city }
17:32:11 <ericP> │ _:a │ _:d │   3.0E1 │ "London" │  "Bob" │
17:32:11 <ericP> │ _:a │ _:f │   3.0E1 │ "London" │  "Bob" │
17:32:11 <ericP> │ _:c │ _:d │   3.0E1 │ "London" │  "Bob" │
17:32:11 <ericP> │ _:c │ _:f │   3.0E1 │ "London" │  "Bob" │
17:32:11 <ericP> │ _:b │ _:e │   2.0E1 │ "Madrid" │  "Sue" │
17:32:13 <Zakim> -dmcneil
17:32:34 <ericP> SELECT * FROM IOUs INNER JOIN Lives ON IOUs.fname=Lives.fname;
17:32:42 <ericP> | Bob   | Smith |     30 | Bob   | Smith | London |
17:32:42 <ericP> | Bob   | Smith |     30 | Bob   | Smith | London |
17:32:42 <ericP> | Sue   | Jones |     20 | Sue   | Jones | Madrid |
17:32:42 <ericP> | Bob   | Smith |     30 | Bob   | Smith | London |
17:32:42 <ericP> | Bob   | Smith |     30 | Bob   | Smith | London |
17:35:09 <mhausenblas> trackbot, end telecon
17:35:09 <trackbot> Zakim, list attendees
17:35:09 <Zakim> As of this point the attendees have been Ashok_Malhotra, mhausenblas, cygri, MacTed, dmcneil, Ivan, nuno, nunolopes, Souri, juansequeda, seema, EricP
17:35:17 <trackbot> RRSAgent, please draft minutes
17:35:17 <RRSAgent> I have made the request to generate http://www.w3.org/2012/05/01-RDB2RDF-minutes.html trackbot
17:35:18 <trackbot> RRSAgent, bye
17:35:18 <RRSAgent> I see no action items