From the checklist at https://wikitech.wikimedia.org/wiki/Schema_changes:
# **ALTERs to run:** https://gerrit.wikimedia.org/r/#/c/322727/3/maintenance/archives/patch-externallinks-el_index_60.sql
# **Where to run those changes:** all.dblist
# **When to run those changes:** No time constraint. But it has been waiting for over a year now.
# **If the schema change is backwards compatible:** Yes. The code to use it is not merged yet.
# **If the schema change has been tested already on some of the test/beta wikis:** It has been auto-deployed to Beta.
# **if the data should be made available on the labs replicas and/or dumps:** The data in this column is public, and can safely be replicated to labs.
* Progress:
** s1
*** [] codfw
*** [] eqiad
** s2
*** [x] codfw
*** [x] eqiad progress: T153182#3985092
** s3
*** [x] codfw
*** [x] eqiad progress: T153182#4096782
** s4
*** [x] codfw
*** [x] eqiad progress: T153182#4034295
** s5
*** [x] codfw progress: T153182#3962541
*** [x] eqiad
** s6
*** [x] codfw
*** [x] eqiad progress: T153182#3977744
** s7
*** [x] codfw
*** [x] eqiad progress: T153182#4023551
** s8
*** [] codfw
*** [] eqiad
** [x] labswiki (m5)
** [x] labtestwiki (labtestweb2001)