В письме от Tue, 08 Nov 2011 15:38:30 +0400, Arioch
<the_ari...@nm.ru> сообщал:
Таблица Objects (integer idx not null Primary key и еще столбцы)
Таблица Metrics (integer idx not null Primary key, integer Object not
null -> FK на Objects.idx, double Turn индексированное);
В ту же копилку, взаимодействие агрегатов и where
select m.object as object_idx, max (m.turn) as max_turn
from metrics m
/* where m.turn > 45 */
group by m.object
having max (m.turn) > 45
order by 2 descending
---
PLAN SORT ((M ORDER FK_METRICS_1))
Indexed Reads: 9351
select m.object as object_idx, max (m.turn) as max_turn
from metrics m
where m.turn > 45
group by m.object
/* having max (m.turn) > 45 */
order by 2 descending
--------------
PLAN SORT ((M ORDER FK_METRICS_1 INDEX (METRICS_IDX2)))
Indexed Reads: 1352
--
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