> > Do you guys welcome contribution on wikitech?
yes please! :) On Tue, Nov 11, 2014 at 11:28 AM, Giovanni Luca Ciampaglia < [email protected]> wrote: > Ah, I didn't know the tables on LabsDB where actually views! That makes > sense now. I guess the documentation should be more explicit on this. Right > now this detail is only mentioned in passing here (emphasis added): > > The revision and logging tables do not have indexes on user columns. In >> an email >> <http://lists.wikimedia.org/pipermail/labs-l/2013-September/001607.html>, >> one of the system administrators pointed out that this is because "those >> values are conditionally nulled when supressed". One has to instead use the >> correspondingrevision_userindex or logging_userindex for these types of >> queries. *On those views*, rows where the column would have otherwise >> been nulled are elided; this allows the indexes to be usable. > > > > > https://wikitech.wikimedia.org/wiki/Help:Tool_Labs/Database#Tables_for_revision_or_logging_queries_involving_user_names_and_IDs > > Do you guys welcome contribution on wikitech? > > G > > > > Giovanni Luca Ciampaglia > > ✎ 919 E 10th ∙ Bloomington 47408 IN ∙ USA > ☞ http://www.glciampaglia.com/ > ✆ +1 812 855-7261 > ✉ [email protected] > > 2014-11-11 8:46 GMT-05:00 Aaron Halfaker <[email protected]>: > > The tables you are access on labs are actually "views". They won't show >> their indexes because they are the result of a query. >> >> Also keep in mind that some views are *not* indexed. >> >> For example, "revision" is not indexed, but "revision_userindex" is. >> Similarly, "logging" is not indexed, but "logging_userindex" is. This is >> confusing and cause for a lot for frustration, but there's good reason. >> See https://bugzilla.wikimedia.org/show_bug.cgi?id=66786 >> >> On Tue, Nov 11, 2014 at 12:23 AM, Giovanni Luca Ciampaglia < >> [email protected]> wrote: >> >>> I know the best place to ask this would be Labs-l, but I just subscribed >>> to it and am waiting for the list admin to be added. In the meanwhile some >>> good soul could please forward this message there? >>> >>> Is there a reason why the tables on the Labs replica are not indexed? >>> Drawing a list of random titles with page_random takes more than a minute! >>> >>> MariaDB [enwiki_p]> select page_id, page_title, page_random from page >>> where page_random > rand() and page_namespace = 0 order by page_random >>> limit 10; >>> +----------+---------------------------------------+----------------+ >>> | page_id | page_title | page_random | >>> +----------+---------------------------------------+----------------+ >>> | 18247710 | Jack_frost_comic | 0.000597330654 | >>> | 2102857 | Prince_Carl_Christian_of_Hohenzollern | 0.000885503126 | >>> | 21550893 | Phoberocyon | 0.000927813129 | >>> | 2836759 | Rinascimento | 0.000943768415 | >>> | 20972414 | Gothic_black_metal | 0.000989090479 | >>> | 1654899 | 1500v_DC | 0.001175443821 | >>> | 43905082 | Juan_García_Costilla | 0.00153940668 | >>> | 1316905 | T_subsurface_stock | 0.001564608112 | >>> | 1447578 | RPGMaker_2000 | 0.00158874586 | >>> | 2034084 | State_Bar_of_California | 0.001697520497 | >>> +----------+---------------------------------------+----------------+ >>> 10 rows in set (1 min 21.14 sec) >>> >>> MariaDB [enwiki_p]> show index from page; >>> Empty set (0.00 sec) >>> >>> MariaDB [enwiki_p]> >>> >>> >>> Giovanni Luca Ciampaglia >>> >>> ✎ 919 E 10th ∙ Bloomington 47408 IN ∙ USA >>> ☞ http://www.glciampaglia.com/ >>> ✆ +1 812 855-7261 >>> ✉ [email protected] >>> >>> _______________________________________________ >>> Wiki-research-l mailing list >>> [email protected] >>> https://lists.wikimedia.org/mailman/listinfo/wiki-research-l >>> >>> >> >> _______________________________________________ >> Wiki-research-l mailing list >> [email protected] >> https://lists.wikimedia.org/mailman/listinfo/wiki-research-l >> >> > > _______________________________________________ > Wiki-research-l mailing list > [email protected] > https://lists.wikimedia.org/mailman/listinfo/wiki-research-l > >
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