UFAL/The new version of the Item must have bigger search priority than old versions

[milanmajchrak]

There is need to create a new Solr plugin following the SolrServiceTweaksPlugin from the v5.

[Paurikova2]

@milanmajchrak I tried a different approach but didn’t get any successful results. I also wrote about it on Slack.

[Paurikova2]

My Notes

Problem:
Commit 0f52e05 does not work.

Goal:
We want to get results from the query and sort them based on two rules:

1. Prioritize items where the title matches the search query (if the user is searching by title).
2. Prioritize newer versions of the items.

What I Tried:

1. Changes from v5:
   The query was changed: Didn’t work. The new query added an OR condition to the console. So when the original query returned 0 results, the additional clauses returned some results – but they weren’t relevant.
   2 Using + to make the query required: After this change, the query became invalid.
2. Added a new Solr parameter versionNumber: Intended to represent the item's version number.
3. Boosting based on match (title, title, versionNumber): Didn’t work. I'm not sure if the boost parameter exists or if it was even applied in this case.
4. Tried sorting based on versionNumber: Results with title matches were not prioritized. Tests failed (chat said this might be due to issues with COUNT and LIMIT when sorting).
5. Tried sorting first by title match, then by versionNumber: The second sort was applied only to items where a match occurred – didn't work. Some forum posts say you can't use two different sorting mechanisms this way.
6. Tried boosting score for title matches, then sorting by score and then by versionNumber: Boosting the title match score didn't work. The second sorting (by version) was applied only among items with the same score.
7. Tried creating a function to increase score based on title match and versionNumber: Didn’t work.

Notes:
Many forums and chats mention using bf (boost functions), but Solr must support the edismax query parser for that.
DSpace doesn’t currently support it – see this issue: DSpace#10494.

Reference:
Here is my full conversation with the community on Slack:
https://dspace-org.slack.com/archives/C3N0VHT6K/p1753286972674359

Persona Note:
When modifying the Solr configuration, don’t forget to copy everything from dspace/solr into your local