Improved Response Time Using the DOMAIN_INDEX_SORT Hint

You can also optimize for response time by using the related DOMAIN_INDEX_SORT hint. Like FIRST_ROWS(n), when queries are optimized for response time, Oracle Text returns the first rows in the shortest time possible.

For example, you can use this hint:

select /*+ DOMAIN_INDEX_SORT */ pk, score(1), col from ctx_tab
            where contains(txt_col, 'test', 1) > 0 order by score(1) desc;

However, this hint is only rule-based. This means that Oracle Text always chooses the index which satisfies the ORDER BY clause. This hint might result in suboptimal performance for queries where the CONTAINS clause is very selective. In these cases, Oracle recommends that you use the FIRST_ROWS(n) hint, which is fully cost-based.