favor a perfect match

wcs/sql.py

@@ -1718,11 +1718,10 @@ with
         tokenized as (select unnest(regexp_split_to_array($1, '\s+')) w),
         super_tokenized as (
             select w,
-                coalesce(perfect.token,
+                coalesce((select plainto_tsquery(perfect.token) from wcs_search_tokens perfect where perfect.token = plainto_tsquery(w)::text),
                          tsquery_agg_or(plainto_tsquery(partial.token) order by partial.token <-> w desc),
                          plainto_tsquery(w)) tokens
             from tokenized
-            left join wcs_search_tokens perfect on perfect.token = plainto_tsquery(w)::text
             left join wcs_search_tokens partial on partial.token % w and w not similar to '%[0-9]{2,}%'
             group by w)
 select tsquery_agg_and(tokens) from super_tokenized;