Hi Peter, thanks for the feedback. Since we are refactoring many things anyways, we will then use Iterations.asList where needed!
Greetings, Sebastian 2013/1/22 Peter Ansell <[email protected]> > On 21 January 2013 19:45, ASF IRC Services <[email protected]> > wrote: > > Members present: sschaffert, westei, Wikier > > > > ---------------- > > Meeting summary: > > ---------------- > > > > 1. Preface > > > > 2. triple store versioning component > > > > 3. branding > > > > 4. triplestore: sKWRL reasoner > > d. https://issues.apache.org/jira/browse/MARMOTTA-9 (sschaffert, 4) > > > > 5. any other business > > > > > > -------- > > Actions: > > -------- > > - add Jira issues for versioning component: deleting old versions and > reverting/undoing a version (sschaffert, 09:17:16) > > - sKWRL goal (Monday, 21/01): redesign data model (sschaffert, 09:32:30) > > - sKWRL goal (Tuesday, 22/02): port the queries to new data model > (sschaffert, 09:32:55) > > > > IRC log follows: > > > > > > # 1. Preface # > > 09:12:02 [sschaffert]: versioning component, reasoning component > > > > > > # 2. triple store versioning component # > > 09:12:48 [sschaffert]: so I'll give a brief report on the progress of > the versioning > > 09:13:00 [Wikier]: good > > 09:13:08 [sschaffert]: the component is now implemented as it was > planned, so I closed MARMOTTA-8 > > 09:13:23 [sschaffert]: the features are; > > 09:13:45 [sschaffert]: - takes a log of all changes done to the triple > store and stores them as versions when a transaction ends (i.e. > connection.commit() is called) > > 09:14:10 [sschaffert]: - versions can be listed (all versions or between > dates) to see the actual changes > > 09:14:46 [Wikier]: cool > > 09:14:53 [sschaffert]: - you can access a snapshot of the repository at > any given point in history (using a Java Date) by requesting a special > repository connection > > 09:15:09 [Wikier]: I think such features would be really useful in many > scenarios > > 09:15:15 [sschaffert]: over this connection you have read-only access to > the snapshot, but you can use the normal repository API including SPARQL > > 09:15:45 [sschaffert]: yes, especially for things like Permalinks to a > version of the repository > > 09:16:08 [sschaffert]: now, things that are still missing in the > versioning component, but not planned for now: > > 09:16:22 [sschaffert]: - deleting old versions (including garbage > collecting deleted triples) > > 09:16:31 [sschaffert]: - reverting/undoing a version > > 09:16:52 [sschaffert]: both features can be implemented at a later > stage, I'll add issues to Jira > > 09:17:16 [sschaffert]: #action add Jira issues for versioning component: > deleting old versions and reverting/undoing a version > > 09:17:24 [Wikier]: perfect > > 09:17:53 [sschaffert]: I have written tests, the test coverage of the > versioning component is about 80-90% > > 09:17:55 [westei]: That would be also a nice feature for the Apache > Stanbol Entityhub > > 09:18:08 [sschaffert]: tested with PostgreSQL, MySQL, H2 > > 09:18:31 [sschaffert]: with the typical limitation of MySQL, which cuts > timestamps at the second (this makes it a bit tricky to query for snapshots) > > 09:18:53 [Wikier]: westei: I see many potential scenarios: LDP-C, > Entity/Cont Hubs of Stanbol, etc. > > 09:19:01 [sschaffert]: yes, I think there are many scenarios where this > kind of snapshot functionality is useful > > 09:19:31 [sschaffert]: the Marmotta implementation is also very > efficient, there is no difference in performance if you access a snapshot > compared to the latest version > > 09:19:46 [Wikier]: that's great > > 09:19:46 [sschaffert]: well, almost no difference > > 09:19:53 [Wikier]: almost xD > > 09:19:54 [sschaffert]: a different SQL statement > > 09:20:15 [sschaffert]: ok, so next topic > > 09:20:30 [westei]: but that also means that you can not delete removed > triples that are still used in snapshot versions > > 09:20:38 [sschaffert]: yes > > 09:20:47 [sschaffert]: this is the garbage collection issue that I > mentioned > > 09:20:54 [westei]: ok > > 09:21:08 [sschaffert]: I'll implement this at a later stage > > > > > > # 3. branding # > > 09:21:31 [Wikier]: my two tasks > > 09:21:45 [sschaffert]: in general, the garbage collection is a bit > tricky, though, because it requires iterating over all triples and checking > if they are used somewhere else > > 09:21:45 [sschaffert]: ok > > 09:22:38 [Wikier]: - source site is ready, awaiting for infra to setup > the site at marmotta.incubator.apache.org (INFRA-5624) > > 09:22:53 [sschaffert]: I already wanted to ask - still getting 404 > > 09:23:24 [Wikier]: - I contacted with trademarks@ regarding MARMOTTA-5, > still awaiting an answer > > 09:24:01 [Wikier]: sschaffert: they need to setup the cms, so that > VirtualHost would be based on the source code at the svn > > 09:24:15 [Wikier]: that's waht missing right now > > 09:24:23 [Wikier]: welcome, dglachs > > 09:24:30 [sschaffert]: welcome :) > > 09:24:53 [Wikier]: so, awaiting regarding both issues > > 09:25:08 [Wikier]: that's all for the moment about the project branding > > 09:25:08 [sschaffert]: ok > > 09:25:15 [Wikier]: next topic? > > > > > > # 4. triplestore: sKWRL reasoner # > > 09:25:40 [sschaffert]: so again my topic: the reasoner > > 09:25:53 [Wikier]: good > > 09:26:00 [sschaffert]: this refers to MARMOTTA-9 > > 09:26:08 [sschaffert]: #link > https://issues.apache.org/jira/browse/MARMOTTA-9 > > 09:26:40 [sschaffert]: the goal is to port the existing sKWRL reasoner > from the current implementation in the LMF over to the KiWi triplestore > > 09:27:01 [sschaffert]: this will be my task until the end of the week > > 09:27:11 [sschaffert]: because it is probably a bit tricky > > 09:27:33 [sschaffert]: the challenge is to remove the Hibernate > dependency > > 09:27:38 [sschaffert]: this requires: > > 09:28:01 [sschaffert]: - designing a new data model for representing the > reasoner; I am still not sure how to store reasoning programs in the > database > > 09:28:23 [sschaffert]: the old version splitted up programs into their > components > > 09:28:38 [sschaffert]: i.e. there was a table for the program, a table > for the rules, a table for each pattern > > 09:29:08 [sschaffert]: and evaluating a reasoning rule was a join over > the pattern table and the triple table > > 09:29:30 [sschaffert]: my idea now is to simplify this and only have one > table where all rules are stored in their parsable syntax > > 09:29:53 [sschaffert]: but I am not yet sure if this has serious > influence on the evaluation, so this needs to be checked > > 09:30:00 [sschaffert]: second requirement: > > 09:30:33 [sschaffert]: - translate query patterns into SQL queries; at > the moment they are evaluated in a dynamically generated HQL query > > 09:31:15 [sschaffert]: this needs a lot of care, and could cause trouble > with different database systems, so I need to think about a proper way to > achieve database independence, maybe using JOOQ > > 09:31:22 [sschaffert]: third requirement: > > 09:31:30 [sschaffert]: - storing justifications properly and efficiently > > 09:31:45 [sschaffert]: this can probably be ported from the existing > implementation > > 09:32:00 [sschaffert]: so goal for today is to develop the new datamodel > > 09:32:30 [sschaffert]: #action sKWRL goal (Monday, 21/01): redesign data > model > > 09:32:55 [sschaffert]: #action sKWRL goal (Tuesday, 22/02): port the > queries to new data model > > 09:33:31 [sschaffert]: and rest of the week the rest, including > designing proper tests and integrating with the transaction system :) > > 09:33:38 [Wikier]: ambitious deadlines ;-) > > 09:33:56 [sschaffert]: doable, since I already know what I am doing :) > > 09:34:16 [sschaffert]: and this time, the code is mostly reusable, so I > don't need to implement the reasoner from scratch > > 09:34:47 [sschaffert]: so, topic finished if there are no questions :) > > 09:35:52 [Wikier]: not now > > 09:36:22 [Wikier]: but at some point, do we plan to be able to use sKWRL > on top of any sesame-based triple store? > > 09:36:37 [westei]: hehe wanted to ask exactly the same question ^^ > > 09:36:47 [Wikier]: ،_، > > 09:36:53 [sschaffert]: yes, but it is of course tightly integrated with > the KiWi implementation because it directly operates on the database > > 09:36:56 [Wikier]: ok > > 09:37:01 [sschaffert]: ah, so the answer is NO > > 09:37:08 [Wikier]: that's what I guess > > 09:37:08 [sschaffert]: unfortunately > > 09:37:24 [sschaffert]: the reason is that the reasoner stores > information about the reasoning process in the database > > 09:37:31 [Wikier]: well, being possitive, one additional feature of the > kiwi triple store > > 09:37:46 [Wikier]: not a really bad conclusion, I mean > > 09:37:47 [sschaffert]: maybe I can explain the data model briefly > tomorrow so you see what I mean > > 09:37:54 [sschaffert]: no, not at all > > 09:38:08 [sschaffert]: this way it is a very efficient reasoner > > 09:38:39 [sschaffert]: so any other topic? > > > > > > # 5. any other business # > > 09:39:32 [sschaffert]: I have a small thing: > > 09:40:08 [sschaffert]: in the new Sesame 2.7.0beta1 there is a bug that > I reported which is still not fixed ( > https://openrdf.atlassian.net/browse/SES-1702) > > 09:40:33 [sschaffert]: the problem is that certain operations on the > repository result of a query do not close the result properly > > 09:40:40 [sschaffert]: which can lead to resource exhaustion > > 09:41:07 [sschaffert]: affected are the convenience methods .asList(), > .asSet() and .addTo(...) > > The new CloseableIteration methods that you are referring to have been > removed in Sesame-2.7.0-beta2-SNAPSHOT, based on feedback from users > (see SES-1678). After they were removed, I added the old > RepositoryResult.asList and .addTo methods back in for backwards > compatibility and deprecated them, in favour of recommending the > methods from the info.aduna.iteration.Iterations helper class. > > > 09:41:15 [Wikier]: at least bug identified > > 09:41:15 [sschaffert]: so don't use them right now :) > > 09:41:30 [Wikier]: hopefully the 2.7 final release will fix it > > 09:41:45 [sschaffert]: in the tests of the versioning component I have > implemented a workaround method asList > > 09:41:47 [sschaffert]: yes > > 09:41:53 [Wikier]: ok, good to know it > > 09:42:16 [sschaffert]: I can maybe move this method to the result > utilities in sesame-commons > > 09:43:00 [Wikier]: Thomas reported me by skype (he can't access irc now) > that he is working on the admin user interface improvement (MARMOTTA-14) > > 09:43:37 [Wikier]: sschaffert: I'd be prefer to wait until the solve it > directly in sesame, it not I agree it could go to the sesame-tools, right > > Could you comment on SES-1702 if the bug is still there in the current > BitBucket Git repository or if the bug comes back. > > > 09:43:45 [Wikier]: let's see... > > 09:43:54 [sschaffert]: yes > > 09:44:01 [Wikier]: ok, any other business? > > 09:44:10 [sschaffert]: not from my side at the moment > > 09:44:30 [Wikier]: ok > > 09:44:38 [Wikier]: next meeting tomorrow 10h00 am cet > > >
