Distinct is a great way to get quick results when writing quick & dirty queries, but I rarely have them perform better than a re-write that avoids the need. It collects a ton of results, orders them, and throws away duplicates in the process. I don't love the idea of that extra work. Did you say you have an index on c1?
select c1, sub1.c2, sub2.c3 from t join lateral (select c2 from t1 where t1.c1 = t.c1 order by c2, c4 limit 1 ) as sub1 on true join lateral (select c3 from t1 where t1.c1 = t.c1 order by coalesce(c4, '000'), c3 limit 1 ) as sub2 on true; > select c1, (select c2 from t1 where t1.c1 = t.c1 order by c2, c4 limit 1 ) AS c2, (select c3 from t1 where t1.c1 = t.c1 order by coalesce(c4, '000'), c3 limit 1 ) AS c3 from t; I don't know the data, but I assume there may be many rows with the same c1 value, so then you would likely benefit from getting that distinct set first like below as your FROM table. *(select c1 from t group by c1 ) AS t*
