On Mon, 6 Mar 2017 at 16:52 MZMcBride <[email protected]> wrote: > For a "regular" MediaWiki installation, will making these changes be a > matter of simply updating MediaWiki's application code and running > maintenance/update.php? >
Yes. > For Wikimedia wikis, as far as I know update.php is never run. Correct; it'd take down the cluster. Are you planning to write separate maintenance scripts for this? > Yes. As is "normal" with schema changes, in Wikimedia production this will be done manually by the DBAs <https://wikitech.wikimedia.org/wiki/Schema_changes>. It is a careful, very slow process that manages the otherwise-impossible. It will take months of their time, is seriously laborious, and blocks any other such changes. A recent user-facing example is T69223 <https://phabricator.wikimedia.org/T69223>, which was required to support translation from non-English languages on multi-content wikis. This is why the DBAs' views are so important. :-) Once the schema change is done, we may/will back-fill old rows to populate the new schema, using maintenance scripts for each wiki. However, given that the table we're talking about is revision with over three quarters of a billion rows on enwiki alone, that will be exceptionally slow-running. Once all *that* is done, we could do a further schema change to drop the old bits of the schema that are no longer used (again, slow), and then drop the backwards-compatible database code from MediaWiki. But that's optional. Regarding scope, this is a lot of changes. How are all of these changes > intended to be divided? Are we able to move forward with some changes > (e.g., adding a comment table) without moving forward with other changes > (e.g., adding a user_entry table)? Yes, but given that this round will take years to complete, deciding to delay some of the things means upsetting a lot of plans. J. -- James D. Forrester Lead Product Manager, Editing Wikimedia Foundation, Inc. jforrester at wikimedia.org <https://lists.wikimedia.org/mailman/listinfo/wikimedia-l> | @jdforrester _______________________________________________ Wikitech-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikitech-l
