Speed up Discussion Search FullTextGambit as it is too slow

[meezaan]

Fixes flarum/issue-archive#240 (potentially)

Changes proposed in this pull request:

The relevance based search in the original gambit has a huge performance impact (a negative one), so it actually makes Flarum unusable on large data sets. As an example, on our database, the original query took 105s to return results. The one in this PR takes 2-3s.

Reviewers should focus on:

Screenshot

Confirmed

• [ x] Frontend changes: tested on a local Flarum installation and in production with 20m posts.
• [ x] Backend changes: tests are green (run composer test).

[meezaan]

So the unit tests will obviously fail because the query is different.

[franzliedke]

Have you experimented with removing other, smaller parts of the query, e.g. the IN BOOLEAN MODE? I would expect a fulltext index to still perform better than a LIKE query.

[franzliedke]

@meezaan Also, can you experiment with reverting #1741 and then amending it so that this test still passes?

[meezaan]

@franzliedke Thanks for the feedback. I will try and find the time to do this, but just FYI I we are working on an Elastic Search extension and that is my priority (because I will be moving on shortly). As it stands, the results we are getting with this SQL are good enough - but other parts slow down with the large data - the Following page, loading large tags, etc. and and there's no text search there - it's the late order by clause that kills us, and what we really want to do is have enough WHERE clauses to reduce the number of results to order. Adding @tariqwalji here who will be taking over from me.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. We do this to keep the amount of open issues to a manageable minimum.
In any case, thanks for taking an interest in this software and contributing by opening the issue in the first place!

[meezaan]

I will close this - this problem has likely been addressed using Elastic Search? @tariqwalji?

[luceos]

We settled on reverting the change that included the discussion subject and will investigate alternative solutions like a delegated search driver (perhaps something similar to Laravel Scout) before (or soon after) stable.

[meezaan]

Thanks @luceos.