Hmm, it appears to still be used to mark notifications as read when certain pages are viewed, at https://phabricator.wikimedia.org/diffusion/ECHO/browse/master/Hooks.php;c82e3905916b77854a00f72155b119adffabb443$788 .

@SBisson Is it right that we still use etp_user there?

In T143959#2584844, @Catrope wrote:

Hmm, it appears to still be used to mark notifications as read when certain pages are viewed, at https://phabricator.wikimedia.org/diffusion/ECHO/browse/master/Hooks.php;c82e3905916b77854a00f72155b119adffabb443$788 .

@SBisson Is it right that we still use etp_user there?

etp_user is technically used to populate and query echo_target_page but it doesn't do anything useful. There is nothing user-specific about the relationship between events and pages that is maintained in this table. We still mark notifications as read when a user visits a page but we don't delete the row associated with this user and that page.

In T143959#2585446, @SBisson wrote:

etp_user is technically used to populate and query echo_target_page but it doesn't do anything useful. There is nothing user-specific about the relationship between events and pages that is maintained in this table. We still mark notifications as read when a user visits a page but we don't delete the row associated with this user and that page.

Right, so I guess we can change that query to find all unread notifications for the user and join against etp to find only the ones relevant to the current page, rather than getting the user's entries in the etp table. I'll work on that.

Change 309051 had a related patch set uploaded (by Sbisson):
[WIP] Remove etp_user

https://gerrit.wikimedia.org/r/309051

Change 309051 merged by jenkins-bot:
Remove etp_user

https://gerrit.wikimedia.org/r/309051

Checked in betalabs as general regression testing. Dropped indexes are not seemed to be used.