From https://wikitech.wikimedia.org/wiki/Schema_changes#Workflow_of_a_schema_change:
- **ALTERs to run**: <https://gerrit.wikimedia.org/g/mediawiki/core/+/992da671a1e/maintenance/archives/patch-page_restrictions-null.sql> (from <https://gerrit.wikimedia.org/r/581141>)
- **Where to run those changes**: all.dblist
- **When to run those changes**: No time constraint.
- **If the schema change is backwards compatible**: Yes. The field is being made nullable in preparation for a future code change that stops inserting values into it.
- **If the schema change has been tested already on some of the test/beta wikis**: No. Autodeployment is likely to push it to beta cluster at some point today (2020/03/23).
- **If the data should be made available on the labs replicas and/or dumps:** N/A, no new data is being added here.
10.4 hosts with the `tinyblob` version need: `alter table page change column page_restrictions page_restrictions tinyblob default NULL;` See T248333#6004421
Schema change progress:
[] s1 tinyblob
** [] eqiad
** [] codfw
[x] s2 tinyblob
** [x] eqiad T248333#6004719
** [x] codfw
[] s3
** [] eqiad
** [] codfw
[] s4 tinyblob
** [] eqiad
** [x] codfw
[x] s5 All varbinary except: enwikivoyage tinyblob
** [x] eqiad T248333#6001279
** [x] codfw
[x] s6 varbinary T248333#5994497
** [x] eqiad
** [x] codfw
[] s7 varbinary
** [] eqiad
** [] codfw
[] s8 tinyblob
** [] eqiad
** [] codfw
[x] wikitech (labswiki)
[] labstestwiki @Andrew