Mention scoring characteristics (#78965)

docs/reference/sql/functions/search.asciidoc

@@ -8,6 +8,11 @@ when the `MATCH` or `QUERY` predicates are being used.
 Outside a, so-called, search context, these functions will return default values
 such as `0` or `NULL`.
 
+{es-sql} optimizes all queries executed against {es} depending on the scoring needs.
+Using <<_track_scores,`track_scores`>> on the search request or <<sort-search-results,`_doc` sorting>> that
+disables scores calculation, {es-sql} instructs {es} not to compute scores when these are not needed.
+For example, every time a `SCORE()` function is encountered in the SQL query, the scores are computed.
+
 [[sql-functions-search-match]]
 ==== `MATCH`