IRC log of rdb2rdf on 2011-02-15

Timestamps are in UTC.

16:47:07 [RRSAgent]
RRSAgent has joined #rdb2rdf
16:47:07 [RRSAgent]
logging to
16:47:09 [trackbot]
RRSAgent, make logs world
16:47:09 [Zakim]
Zakim has joined #rdb2rdf
16:47:11 [trackbot]
Zakim, this will be 7322733
16:47:11 [Zakim]
ok, trackbot; I see SW_RDB2RDF()12:00PM scheduled to start in 13 minutes
16:47:12 [trackbot]
Meeting: RDB2RDF Working Group Teleconference
16:47:12 [trackbot]
Date: 15 February 2011
16:47:19 [ivan]
Chair: Ivan
16:47:28 [ivan]
Regrets: Boris, Michael, Ashok
16:52:43 [ivan]
Regrets+ Sören
16:56:26 [dmcneil]
dmcneil has joined #RDB2RDF
16:58:37 [Zakim]
SW_RDB2RDF()12:00PM has now started
16:58:44 [Zakim]
16:58:51 [ivan]
zakim, dial ivan-voip
16:58:51 [Zakim]
ok, ivan; the call is being made
16:58:52 [Zakim]
16:58:52 [Zakim]
16:58:52 [Zakim]
16:59:26 [ivan]
Topic: admin issues
16:59:40 [Zakim]
17:00:09 [privera]
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17:00:12 [Zakim]
17:00:55 [cygri]
cygri has joined #rdb2rdf
17:01:27 [juansequeda]
juansequeda has joined #rdb2rdf
17:01:41 [Zakim]
17:01:53 [Zakim]
17:01:55 [Zakim]
17:02:20 [privera]
zakim, mute me
17:02:20 [Zakim]
sorry, privera, I do not know which phone connection belongs to you
17:02:40 [ivan]
zakim, IPcaller is privera
17:02:40 [Zakim]
+privera; got it
17:02:50 [privera]
zakim, mute me
17:02:50 [Zakim]
privera should now be muted
17:03:01 [Zakim]
17:03:32 [Seema]
Seema has joined #rdb2rdf
17:03:41 [Souri]
Souri has joined #rdb2rdf
17:03:59 [ivan]
zakim, who is here?
17:04:00 [Zakim]
On the phone I see dmcneil, Ivan, Alexandre, EricP, privera (muted), Souri
17:04:02 [Zakim]
On IRC I see Souri, Seema, juansequeda, cygri, privera, dmcneil, Zakim, RRSAgent, ivan, betehess, LeeF, MacTed, iv_an_ru, trackbot, ericP
17:04:15 [Zakim]
+ +1.603.897.aaaa
17:04:32 [betehess]
Zakim, aaaa is Seema
17:04:32 [Zakim]
+Seema; got it
17:04:50 [Zakim]
17:05:16 [ivan]
zakim, mhausenblas is cygri
17:05:16 [Zakim]
+cygri; got it
17:05:32 [ivan]
zakim, pick a victim
17:05:32 [Zakim]
Not knowing who is chairing or who scribed recently, I propose dmcneil
17:06:00 [ivan]
scribenick: dmcneil
17:06:13 [ericP]
dmcneil: i can scribe
17:06:15 [ericP]
... but i need to know the incantations
17:06:22 [Ashok]
Ashok has joined #rdb2rdf
17:07:00 [ivan]
topic: admin
17:07:12 [dmcneil]
ivan: starting meeting with admin
17:07:18 [ivan]
last week's minutes:
17:07:20 [Zakim]
17:07:54 [ericP]
i second minutes
17:07:57 [betehess]
17:07:59 [dmcneil]
ivan: meetings are accepted
17:08:12 [dmcneil]
ivan: minutes are accepted
17:08:38 [dmcneil]
ivan: test cases are on the agenda, but Boris sent his regrets
17:08:52 [dmcneil]
ivan: any test case related issues for the call?
17:09:08 [betehess]
/me would like to thank Boris for participating to
17:09:09 [dmcneil]
ericP: we can still try out the test cases and see if they make sense
17:09:27 [dmcneil]
ivan: proposes moving to R2RML issues
17:09:28 [ivan]
Topic: R2RML
17:09:32 [Ashok]
RESOLUTION: Minutes from last week are accepted
17:09:55 [Souri]
We can discuss ISSUE-23 raised by David
17:10:09 [ivan]
17:10:09 [trackbot]
ISSUE-23 -- Make tableOwner optional -- raised
17:10:09 [trackbot]
17:10:37 [ericP]
scribenick: ericP
17:11:13 [ericP]
dmcneil: current R2RML spec requires the tableowner set when using tablename
17:11:14 [ivan]
17:11:16 [Souri]
17:11:21 [ivan]
ack Souri
17:11:32 [ericP]
... propose to make it optional to reflect SQL practice
17:11:45 [ericP]
Souri: discussed with seema and @@1.
17:11:59 [ericP]
... it makes sense for it to be optional
17:12:32 [ericP]
... at query processing time, we'll be connected so we can resolve this via a query time binding
17:12:45 [ericP]
ivan: clear what doc mod is required?
17:12:55 [ericP]
Souri: yep, we just change the cardinality
17:13:03 [ericP]
q+ to ask about SQL connectivity
17:13:18 [cygri]
+1 from me
17:13:41 [ericP]
scribenick: dmcneil
17:13:57 [Souri]
PROPOSE: make rr:tableOwner property optional (that is, have a cardinality of 0 or 1)
17:14:04 [Ashok]
Souri: Recommends that the WG accept the proposed solution to Issue-23
17:14:06 [ivan]
17:14:09 [cygri]
17:14:12 [Souri]
17:14:16 [betehess]
17:14:21 [ivan]
RESOLVED: make rr:tableOwner property optional (that is, have a cardinality of 0 or 1)
17:16:12 [dmcneil]
cygri: do we need to keep an issue open to include this in testing? (paraphrased by ericP)
17:17:02 [dmcneil]
Ashok: ISSUE-23 is not open, create an action to apply it
17:17:05 [ivan]
ACTION: Souri to implement the conditionality of table ownder
17:17:05 [trackbot]
Sorry, couldn't find user - Souri
17:17:10 [Souri]
17:17:39 [ivan]
ACTION: sdas2 to implement the conditionality of table ownder
17:17:39 [trackbot]
Created ACTION-103 - Implement the conditionality of table ownder [on Souripriya Das - due 2011-02-22].
17:17:54 [ivan]
17:17:54 [trackbot]
ISSUE-92 does not exist
17:18:05 [ivan]
17:18:05 [trackbot]
ACTION-92 -- Richard Cyganiak to address the R2RML - DM connection -- due 2011-02-08 -- OPEN
17:18:05 [trackbot]
17:18:40 [dmcneil]
cygri: haven't done it yet, quite a bit of traffic on mailing list, need to think about how to do it in the document
17:19:12 [dmcneil]
cygri: there was a discussion about whether there should be a primer, or something that explains how the working group deliverables work together
17:19:14 [ivan]
17:19:18 [Zakim]
+ +575737aabb
17:19:26 [juansequeda]
zakim, aabb is me
17:19:26 [Zakim]
+juansequeda; got it
17:19:28 [dmcneil]
cygri: perhaps this could be addressed in the primer (or overview doc)
17:19:59 [Ashok]
17:20:03 [dmcneil]
cygri: or we could just add a bit of text to each of the docs
17:20:23 [ivan]
ack ivan
17:20:27 [ericP]
17:20:47 [dmcneil]
ericP: withdraws question regarding whether a connection exists at times of query rewriting
17:21:11 [dmcneil]
ivan: strongly in favor of an overview/primer document
17:21:32 [ivan]
ack Ashok
17:21:44 [dmcneil]
Ashok: yes, we should write a primer, but people might not read it
17:21:53 [ivan]
17:22:06 [dmcneil]
Ashok: also, add at least one paragraph to each doc talking about the relationships between the docs
17:22:24 [ericP]
OWL primer?
17:22:25 [dmcneil]
ivan: may not agree
17:22:28 [ivan]
17:23:10 [dmcneil]
ivan: points to the OWL document that is brief (1.5 pages) that shows how all of the pieces fit together
17:23:17 [juansequeda]
+1 to an overview document
17:23:23 [dmcneil]
ivan: this document was well received
17:23:23 [cygri]
17:23:32 [ivan]
ack ivan
17:23:35 [betehess]
q+ to comment quickly on how we could use the spec grouping feature, like
17:23:50 [ivan]
ack cygri
17:24:40 [dmcneil]
cygri: probably a short document because there is not a long list of deliverables (like OWL), but it will make it seem more complicated
17:24:54 [dmcneil]
cygri: if it can be addressed easily in the main document, then it is a good idea
17:25:13 [dmcneil]
cygi: the main documents are Direct Mapping and R2RML documents
17:25:35 [dmcneil]
cygri: different paragraph in each referring to the other
17:26:04 [Souri]
17:26:05 [dmcneil]
cygri: this would produce a more usable set of documents
17:26:40 [dmcneil]
cygri: could try putting the content in the wiki and then assess whether it warrants a separate document
17:26:43 [ivan]
ack betehess
17:26:43 [Zakim]
betehess, you wanted to comment quickly on how we could use the spec grouping feature, like
17:27:09 [betehess]
17:27:16 [dmcneil]
betehess: it is possible to create a new group to have all the specification in one group
17:27:40 [ivan]
17:27:46 [dmcneil]
betehess: dependencies between documents is difficult to manage
17:28:11 [ivan]
ack Souri
17:28:12 [cygri]
17:28:29 [cygri]
17:28:51 [dmcneil]
Souri: the R2RML document needs to be extended to describe how direct mappings can be used in a custom mapping
17:29:00 [betehess]
/me would like to recall we'll also have a document for the tests
17:29:09 [dmcneil]
Souri: need examples/test cases that show such hybrid mappings, this could go in a "primer"
17:29:31 [betehess]
ivan, open an issue :-)
17:29:34 [ericP]
17:29:43 [ivan]
ack ericP
17:29:44 [Souri]
illustrating hybrid mappings (some portion R2RML, some portion DM)
17:29:50 [juansequeda]
17:30:05 [ivan]
17:30:06 [dmcneil]
ericP: currently the Direct Mapping refers to the R2RML spec
17:30:23 [ivan]
ack juansequeda
17:30:29 [dmcneil]
ericP: the R2RML spec will need a reference to the Direct Mapping for the feature of using Direct Mappings in a custom mapping
17:30:35 [dmcneil]
ericP: so this will be covered anyway
17:30:54 [ivan]
ack ivan
17:30:57 [dmcneil]
juansequeda: short, summary document could be a good thing for the wider community
17:31:41 [dmcneil]
ivan: a summary document that clearly shows where to start reading makes sense
17:32:11 [ivan]
17:32:11 [trackbot]
ACTION-93 -- Souripriya Das to identify not-mapping vs. default-mapping issues in R2RML/DM (Wiki or via mail) -- due 2011-02-08 -- OPEN
17:32:11 [trackbot]
17:32:13 [dmcneil]
ivan: re-interpret ACTION-92 to be write proposed content on the wiki
17:32:38 [dmcneil]
Souri: discussed general approach last week, haven't worked on it much, not difficult to get done
17:32:45 [ivan]
17:32:45 [trackbot]
ACTION-97 -- Richard Cyganiak to look into D2RQ implementation and update -- due 2011-02-08 -- OPEN
17:32:45 [trackbot]
17:32:47 [dmcneil]
Souri will write down more details
17:32:58 [dmcneil]
on Action-93
17:33:41 [dmcneil]
cygri: ACTION-97 is to document how D2RQ supports translation tables
17:34:02 [dmcneil]
ivan: why is this relevant?
17:34:44 [dmcneil]
cygri: charter requires that we try and re-use entity URIs, question is how to get external URIs into the output of the mapping
17:34:48 [ivan]
17:34:48 [trackbot]
ACTION-96 -- Richard Cyganiak to capture this (multiple subject maps) and other (future) potential error cases in the Wiki (ISSUE-16) -- due 2011-02-08 -- OPEN
17:34:48 [trackbot]
17:35:12 [ivan]
17:35:12 [trackbot]
ISSUE-16 -- Should we allow multiple subjects for a logical table row? Also, what if no subject is specified? -- open
17:35:12 [trackbot]
17:35:44 [dmcneil]
cygri: ACTION-96 - since R2RML is expressed in RDF and there is not a schema that clearly expresses what is valid, wanted to collect cases where cardinality was violated
17:36:09 [dmcneil]
cygri: we decided to collect such cases on a wiki page (e.g. "problem multiple subject maps")
17:36:29 [dmcneil]
cygri: for each of those we could document the solution (e.g. "raise error", etc.)
17:36:30 [Zakim]
17:36:33 [juansequeda_]
juansequeda_ has joined #rdb2rdf
17:36:52 [dmcneil]
cygri: then we could use the wiki page contents to drive the specs
17:37:08 [Zakim]
17:37:10 [dmcneil]
cygri: agrees to keeping this action item open
17:37:39 [Souri]
We need to prioritize ... and in my opinion, Primer should come later (we can start on it, but), we need to push out the next draft sooner
17:37:45 [dmcneil]
ivan: the R2RML editor's draft is quite different from the official draft
17:37:49 [Souri]
17:37:54 [cygri]
17:37:58 [dmcneil]
ivan: when can we produce the next official draft
17:38:21 [ivan]
ack Souri
17:38:27 [dmcneil]
ivan: the gap between the two drafts is so large that an updated draft needs to be done soon
17:38:53 [dmcneil]
Souri: agrees, and thinks the official draft can be updated with issues marked
17:39:15 [ivan]
ack cygri
17:39:23 [dmcneil]
Souri: ISSUE-93 - the constructs for hybrid maps is still not defined, but this can be marked as still "in progress"
17:39:38 [Zakim]
+ +1.512.484.aacc
17:39:44 [Zakim]
17:39:58 [dmcneil]
cygri: there has been good progress on the Direct Mapping, might be a draft soon, might be able to publish them together?
17:39:58 [betehess]
we should fix a date where we publish both documents
17:40:17 [betehess]
+1 to ivan :-)
17:40:23 [cygri]
+1 to publishing at same time
17:40:26 [dmcneil]
ivan: very much in favor of publishing the two documents together, let's return to the Direct Mapping in a moment
17:40:38 [privera]
zakim, aacc is juansequeda
17:40:38 [Zakim]
+juansequeda; got it
17:40:49 [betehess]
ivan, we should publish the test-suite NOTE
17:41:11 [dmcneil]
is that juan talking?
17:41:38 [dmcneil]
juansequeda: will be traveling to Chile soon and will get a large amount of work done then
17:41:47 [Zakim]
17:41:50 [dmcneil]
juansequeda: on the Direct Mapping doc (?)
17:41:59 [Souri]
17:42:03 [Souri]
17:42:08 [ivan]
Topic: Direct Mapping
17:42:18 [dmcneil]
ivan: let's not fix a precise date now
17:42:19 [Zakim]
17:42:27 [ivan]
17:42:27 [trackbot]
ACTION-98 -- Juan Sequeda to rename Issue 11 and fix it in the DM -- due 2011-02-08 -- OPEN
17:42:27 [trackbot]
17:42:31 [dmcneil]
ivan: on to the Direct Mapping, 3 open actions
17:42:33 [juansequeda]
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17:42:50 [ivan]
17:42:50 [trackbot]
ISSUE-11 -- Primary Key is a Foreign Key -- open
17:42:50 [trackbot]
17:43:08 [dmcneil]
juansequeda: I did ACTION-98 already
17:43:44 [dmcneil]
juansequesa: this issue was where "foreign key" was incorrectly typed as "candidate key" in the spec
17:43:52 [ivan]
17:43:52 [trackbot]
ACTION-99 -- Juan Sequeda to change ISSUE-13 to postponed and add ref from ISSUE-11 to ISSUE-13 -- due 2011-02-08 -- OPEN
17:43:52 [trackbot]
17:44:05 [dmcneil]
juansequeda: the issue is still open (re ACTION-98)
17:44:08 [Ashok]
Trackbot, Close ACTION-98
17:44:08 [trackbot]
ACTION-98 Rename Issue 11 and fix it in the DM closed
17:44:12 [ivan]
17:44:12 [trackbot]
ACTION-102 -- Ted Thibodeau to sum up the possibilities for generating reliable URIs for DM (to avoid bNodes) on the Wiki -- due 2011-02-15 -- OPEN
17:44:12 [trackbot]
17:44:52 [dmcneil]
ivan: ACTION-102 still open because Ted is not here
17:45:01 [dmcneil]
ivan: what is the status of the Direct Mapping?
17:45:42 [dmcneil]
ericP: there is not much new information, new information will come from Juan's work in Chile (with Marcello (?))
17:46:23 [dmcneil]
ericP: an open question is whether the Direct Mapping produces persistent identifiers for rows without primary keys
17:46:52 [dmcneil]
juansequeda: there is still an open issue related to avoiding blank nodes
17:47:28 [dmcneil]
juansequeda: there are several issues that we can begin discussing: e.g. hierarchical relationships, etc.
17:47:42 [betehess]
the denotational semantics does *not* need a primary key and uses bnode very well
17:47:45 [dmcneil]
ivan: would like to come back to the publication issue before the end of the call
17:47:54 [dmcneil]
ivan: what open issues to dicsuss now?
17:48:16 [dmcneil]
ericP: maybe we can knock off the "primary key is a foreign key" issue
17:49:27 [betehess]
you can try hier_table in with and without "Detects hierarchy relation"
17:49:36 [dmcneil]
ericP: there was a model for the mapping, the considered the case of whether a primary key is also a foreign key, this is one of the 3 ways users express hierarchies in RDBMS, created a solution for expressing this in the mapping
17:50:46 [dmcneil]
ericP: the behavior with "detects hierarchy" turned off is the simple behavior
17:50:49 [juansequeda]
q+ to discuss the three possible cases
17:51:07 [ivan]
ack juansequeda
17:51:07 [Zakim]
juansequeda, you wanted to discuss the three possible cases
17:51:12 [dmcneil]
ericP: the proposal is that this simple behavior be the behavior that is implemented when a primary key is a foreign key
17:51:42 [dmcneil]
juansequeda: there are three possibilities: 1) always detect hierarchy 2) never detect as hierarchy 3) make it an option to detect this as a hierarchy
17:52:01 [betehess]
ivan, yes
17:52:04 [dmcneil]
ivan: how would option "3" work, the beauty of the Direct Mapping is it just works
17:52:16 [dmcneil]
juansequeda: there could be "flavors" of direct mappings
17:52:17 [betehess]
q+ to say I'm against any switch
17:52:33 [dmcneil]
ivan: would rather not see a switch (personal opinion)
17:52:44 [ivan]
ack betehess
17:52:44 [Zakim]
betehess, you wanted to say I'm against any switch
17:52:55 [dmcneil]
betehess: agrees with ivan
17:53:22 [ivan]
17:53:23 [juansequeda]
17:53:38 [cygri]
+1 to have only one flavour. if you want switches, go to r2rml, it has plenty
17:53:43 [dmcneil]
betehess: put the switch into the demo application to show what is being discussed, not to advocate for a switch in the Direct Mapping
17:53:46 [ivan]
ack ivan
17:54:13 [dmcneil]
ivan: proposes publishing the document with the simplest approach, put in a statement that this is still an open issue, ask community for feedback
17:54:19 [ivan]
ack juansequeda
17:54:21 [betehess]
sounds like a wise proposal
17:54:23 [ericP]
q+ to say we've already done one round without feedback
17:54:26 [dmcneil]
juansequeda: agrees with ivan
17:54:30 [ivan]
ack ericP
17:54:30 [Zakim]
ericP, you wanted to say we've already done one round without feedback
17:54:35 [privera]
17:54:36 [dmcneil]
Ashok: agrees with ivan
17:54:48 [dmcneil]
ericP: we tried that, and the community did not respond
17:55:01 [dmcneil]
ericP: so proposes that we just go with the simple solution
17:55:15 [dmcneil]
ivan: has no problem with that
17:56:15 [dmcneil]
ericP: the compromise is that most primary keys appear as literals in the output triples
17:56:39 [juansequeda]
ericP, which example are you talking about?
17:56:51 [dmcneil]
ericP: but id the PK is also a FK then it appears only as a reference to another tuple
17:57:33 [dmcneil]
17:58:49 [dmcneil]
cygri: in general agrees with proposal to proceed, there wasn't a really clear answer, so simplest is safest
17:59:13 [Souri]
To me pk=fk case seems to indicate presence of a simple 1:1 join between a parent table and a child table (which often appears in a normalized DB design) ... is there much more to it?
17:59:15 [ericP]
PROPOSAL: unary primary keys which are also foreign keys are treated exactly as other unary foreign keys
17:59:18 [betehess]
for the record, this is were we don't take unary foreign key in the scalars function:
17:59:30 [betehess]
s/is were/is where/
17:59:44 [ivan]
17:59:49 [ericP]
18:00:11 [Souri]
18:00:15 [juansequeda]
18:00:15 [betehess]
18:00:17 [dmcneil]
18:00:18 [privera]
18:00:20 [ivan]
RESOLVED: unary primary keys which are also foreign keys are treated exactly as other unary foreign keys
18:00:22 [Souri]
0 (not fully clear)
18:00:41 [dmcneil]
ivan: can we stay on for a few minutes to discuss publishing Direct Mapping
18:01:15 [ericP]
q+ to suggest we lose review attention
18:01:25 [dmcneil]
ivan: proposes that the Direct Mapping document be published at the same time as the R2RML document without the Chilean work from Juan
18:01:27 [betehess]
are the r2rml people ready to publish too?
18:01:38 [ivan]
ack ericP
18:01:38 [Zakim]
ericP, you wanted to suggest we lose review attention
18:01:45 [dmcneil]
juansequeda: progress has been made since the current workign draft
18:01:48 [ivan]
18:02:12 [ericP]
ack ivan
18:02:12 [dmcneil]
ericP: fears publishing document with few changes because it endangers the public review capacity
18:02:20 [Souri]
I am ok with publishing R2RML next draft alone
18:02:52 [betehess]
+1 to ivan comment re: publication of both documents makes sense
18:02:55 [dmcneil]
ivan: agrees with respect to Direct Mapping, but R2RML doc has changed a lot, needs to be published soon, is a good habit to publish them together
18:03:44 [dmcneil]
betehess: agrees with ivan
18:03:55 [dmcneil]
ericP: thinks the review capacity is more important
18:04:04 [dmcneil]
ivan: meeting is adjourned
18:04:06 [privera]
+1 to member:ivan comment re: publication of both documents makes sense
18:04:08 [cygri]
great job dmcneil!
18:04:14 [Zakim]
18:04:21 [ericP]
PROPOSED: dmcneil is scribe for life
18:04:22 [dmcneil]
Ashok: will publish minutes
18:04:23 [betehess]
18:04:27 [ivan]
zakim, bye
18:04:27 [Zakim]
leaving. As of this point the attendees were dmcneil, Ivan, Alexandre, EricP, privera, Souri, +1.603.897.aaaa, Seema, cygri, Ashok_Malhotra, +575737aabb, juansequeda,
18:04:27 [Zakim]
Zakim has left #rdb2rdf
18:04:30 [juansequeda]
18:04:30 [Zakim]
... +1.512.484.aacc
18:04:42 [ericP]
18:04:42 [Ashok]
rrsagent, make logs public
18:04:55 [juansequeda]
ericP, I think dmcneil has been the best scribe ever!
18:04:57 [Ashok]
rrsagent, draft minutes
18:04:57 [RRSAgent]
I have made the request to generate Ashok
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