It’s not clear to me what the scope of this task is. As far as I can tell, the task title (migrate to use elastic) is actually fulfilled right now, but the comments in the patch point out several issues, and I’m not sure which ones of them should be part of this issue.

• Special:ItemDisambiguation now does a prefix search, is case insensitive, and also supports searching for entity IDs instead of labels. I assume we want to revert all three of those changes? That could be done with a post-processing step after the main search.
• The special page now uses a class from the API namespace (Wikibase\Repo\Api\EntitySearchHelper), which is a bit smelly – perhaps that class should move somewhere else. But is that part of this task?
• Do we need to keep this special page at all, or should we investigate its uses and potentially remove it completely?
• The gerrit comments also mention list=wbsearch in the API, is that related to this task?

In T195755#4258208, @Lucas_Werkmeister_WMDE wrote:

It’s not clear to me what the scope of this task is. As far as I can tell, the task title (migrate to use elastic) is actually fulfilled right now, but the comments in the patch point out several issues, and I’m not sure which ones of them should be part of this issue.

• Special:ItemDisambiguation now does a prefix search, is case insensitive, and also supports searching for entity IDs instead of labels. I assume we want to revert all three of those changes? That could be done with a post-processing step after the main search.

Yes.

• The special page now uses a class from the API namespace (Wikibase\Repo\Api\EntitySearchHelper), which is a bit smelly – perhaps that class should move somewhere else. But is that part of this task?
• Do we need to keep this special page at all, or should we investigate its uses and potentially remove it completely?

The huge amount of requests to it seem to come through installations of https://github.com/asciimoo/searx - especially framabee - in order to display infobox-like panels on search result pages. We should definitely continue to support this. Question is if this should go through Special:ItemDisambiguation or use some other mechanism.

• The gerrit comments also mention list=wbsearch in the API, is that related to this task?

• The gerrit comments also mention list=wbsearch in the API, is that related to this task?

If I understand correctly, that shouldn’t be a problem after all.

I created some subtasks for the next steps, but IMHO only T196991: Restore old behavior of Special:ItemDisambiguation is required for T195754: Re-enable Special:ItemDisambiguation.

In T195755#4258676, @Lydia_Pintscher wrote:

Question is if this should go through Special:ItemDisambiguation or use some other mechanism.

They should use action=wbsearchentities (like https://www.wikidata.org/w/api.php?action=wbsearchentities&search=abc&language=en) instead of hitting the special page.