Add Support for "track_total_hits" to Accurately Track Total Hits Above 10K

[nikolaysm]

Issue: Django Haystack currently does not support the track_total_hits parameter, leading to inaccurate hit counts when the total exceeds 10,000 (due to Elasticsearch's default limit).

Suggestion: We can add an option in the Elasticsearch backend to enable track_total_hits, allowing users to get accurate total hit counts above 10,000.

if settings.TRACK_TOTAL_HITS: 
    search_kwargs["track_total_hits"] = "true"

This could be added within the search method of elasticsearch_backend.py, allowing users to enable accurate hit tracking.

Reference: Elasticsearch: Track Total Hits

[acdha]

That would be a good first pull-request. I might also want to think about how it could be made optional for a query as track_total_hits is not enabled by default to improve performance and some users might want to be selective about when they use it.

[nikolaysm]

That would be a good first pull-request. I might also want to think about how it could be made optional for a query as track_total_hits is not enabled by default to improve performance and some users might want to be selective about when they use it.

If I were to add this feature, I would include a setting in settings.py:

HAYSTACK_TRACK_TOTAL_HITS = False

This would default to False for performance reasons. If set to True, track_total_hits would be enabled in the search method. I'll draft the pull request with these changes and update the documentation accordingly as soon as possible.

Thanks again for the suggestion!