From the checklist at https://wikitech.wikimedia.org/wiki/Schema_changes:
- ALTERs to run: https://gerrit.wikimedia.org/r/#/c/357892/14/maintenance/archives/patch-comment-table.sql (note there are some CREATEs in there too)
- Where to run those changes: all.dblist
- When to run those changes: No time constraint.
- If the schema change is backwards compatible: Yes. The new columns and tables won't be used until a feature flag is enabled.
- If the schema change has been tested already on some of the test/beta wikis: It appears to have been auto-deployed to Beta. Things seem to be working in some quick testing, and if anyone has complained about things breaking I haven't heard it.
- if the data should be made available on the labs replicas and/or dumps: Treatment of replicas and dumps are the same.
- All columns in the comment table can be made available without restriction. Rows must only be available if they are publicly referenced from one of the _id columns being added in this patch, as mentioned in T153333#3238701 and T153333#3238821. Extensions converted to have _id columns will eventually need to be added to that list. Note: From the MediaWiki side, this table should receive manly INSERTs, no UPDATEs, and DELETEs only due to potential maintenance.
- All columns in revision_comment_temp can be made available without restriction. Rows must only be available if the corresponding revision table row exists (join on revcomment_rev = rev_id) and has (rev_deleted & 2) = 0. Note: From the MediaWiki side, this table should receive INSERTs and DELETEs but no UPDATEs.
- All columns in image_comment_temp can be made available without restriction. Rows must only be available if the corresponding image table row exists (join on imgcomment_name = img_name). Note: From the MediaWiki side, this table should receive INSERTs and DELETEs but no UPDATEs.
- All the _id columns added to existing tables should be available under the same conditions as the corresponding column without the _id suffix. These seem to be:
- archive.ar_comment_id: Never available.
- ipblocks.ipb_reason_id: Always available (whenever the row itself is).
- oldimage.oi_description_id: Available when (oi_deleted & 2) = 0.
- filearchive.fa_description_id: Available when (fa_deleted & 2) = 0.
- filearchive.fa_deleted_reason_id: Always available.
- recentchanges.rc_comment_id: Available when (rc_deleted & 2) = 0.
- logging.log_comment_id: Available when (log_deleted & 2) = 0.
- protectedtitles.pt_reason_id: Always available.
- Progress:
- s1
- codfw
- eqiad T174569#3837301
- s2
- codfw
- eqiad T174569#3787775
- s3
- codfw
- eqiad T174569#3787775
- s4
- codfw
- eqiad T174569#3830446
- s5
- codfw
- eqiad T174569#3889045 (only the master pending)
- s6
- codfw
- eqiad
- s7
- codfw
- eqiad T174569#3866346
- s8
- codfw
- eqiad T174569#3901995
- labswiki (silver)
- labtestwiki (labtestweb2001)
- Filter columns on: modules/role/files/mariadb/filtered_tables.txt
- s1