Hello,
We have communicated https://lists.wikimedia.org/hyperkitty/list/wikitech-l@lists.wikimedia.org/message/JFMU43374T64BTJWI6WLZKLOJ4FL4PRP/ this change in August 2022 but here is a reminder that if you query externallinks table in wikireplicas, you will need to rework your queries.
Changes are: el_to, el_index and el_index_60 fields will be dropped and you need to query el_to_domain_index and el_to_path fields instead.
The data has been migrated in all wikis except English Wikipedia, Wikimedia Commons and Wikidata, you can keep track of the data migration in T326314 https://phabricator.wikimedia.org/T326314.
In late June, we will stop updating the old fields and will start dropping them
This is done to optimize storage of external links (drastically reducing its size by removing duplication) and enabling user requested features such as resolving two https://phabricator.wikimedia.org/T14810 fifteen-year-old tickets https://phabricator.wikimedia.org/T17218 or easier aggregating of external links domain [1], something that wasn’t possible until now.
[1] For example, If you want to get list of the top-linked websites, you can query `SELECT el_to_domain_index, count(*) from externallinks group by el_to_domain_index order by count(*) desc limit 50;`
Thank you and sorry for the inconvenience.