On Mon, Sep 19, 2011 at 10:39 PM, Daniel Friesen <li...@nadir-seen-fire.com> wrote: > On 11-09-19 06:39 PM, Anthony wrote: >> On Mon, Sep 19, 2011 at 3:57 PM, Brion Vibber <br...@pobox.com> wrote: >>> That's probably the simplest solution; adding a new empty table will be very >>> quick. It may make it slower to use the field though, depending on what all >>> uses/exposes it. >> Isn't adding a new column with all NULL values quick too? > Apparently in InnoDB a table ALTER requires an entire copy of the table > to do. In other words to do a table alter every box doing it needs to be > able to hold the entire Wikipedia revision table twice to add a new column.
Ah, okay. I remember that's what happened in MyISAM but I figured they had that fixed in InnoDB. On Mon, Sep 19, 2011 at 3:57 PM, Brion Vibber <br...@pobox.com> wrote: > During stub dump generation for instance this would need to add a left outer > join on the other table, and add things to the dump output (and also needs > an update to the XML schema for the dump format). This would then need to be > preserved through subsequent dump passes as well. Doesn't the stub dump generation computer have its own database? I still don't see the point of putting all this extra work on the master database in order to maintain a function-based index which is only being used for dumps. The dump generation computer should have its own database. For most of the tables/dumps (probably all but the full-text ones), you could even use sqlite and offer that as a download option for those who aren't stuck in 1998. On Tue, Sep 20, 2011 at 3:23 AM, Daniel Friesen <li...@nadir-seen-fire.com> wrote: > On 11-09-19 11:43 PM, Domas Mituzas wrote: >> so, what are the use cases and how does one index for them? is it global >> hash check, per page? etc > One use case I know if is this bug: > https://bugzilla.wikimedia.org/show_bug.cgi?id=2939 Calculating and storing checksums on every revision in the database is way overkill for that. _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l
