我有一个问题:
SELECT DISTINCT ON (analytics_staging_v2s.event_type, sent_email_v2s.recipient, sent_email_v2s.sent) sent_email_v2s.id, sent_email_v2s.user_id, analytics_staging_v2s.event_type, sent_email_v2s.campaign_id, sent_email_v2s.recipient, sent_email_v2s.sent, sent_email_v2s.stage, sent_email_v2s.sequence_id, people.role, people.company, people.first_name, people.last_name, sequences.name as sequence_name
FROM "sent_email_v2s"
LEFT JOIN analytics_staging_v2s ON sent_email_v2s.id = analytics_staging_v2s.sent_email_v2_id
JOIN people ON sent_email_v2s.person_id = people.id
JOIN sequences on sent_email_v2s.sequence_id = sequences.id
JOIN users ON sent_email_v2s.user_id = users.id
WHERE "sent_email_v2s"."status" = 1
AND "people"."person_type" = 0
AND (sent_email_v2s.sequence_id = 1888) AND (sent_email_v2s.sent >= '2016-03-18')
AND "users"."team_id" = 1
当我在上面运行EXPLAIN ANALYZE时,我得到:
然后,如果我将其更改为以下内容(只需删除(sent_email_v2s.sent> =' 2016-03-18')),如下所示:
SELECT DISTINCT ON (analytics_staging_v2s.event_type, sent_email_v2s.recipient, sent_email_v2s.sent) sent_email_v2s.id, sent_email_v2s.user_id, analytics_staging_v2s.event_type, sent_email_v2s.campaign_id, sent_email_v2s.recipient, sent_email_v2s.sent, sent_email_v2s.stage, sent_email_v2s.sequence_id, people.role, people.company, people.first_name, people.last_name, sequences.name as sequence_name
FROM "sent_email_v2s"
LEFT JOIN analytics_staging_v2s ON sent_email_v2s.id = analytics_staging_v2s.sent_email_v2_id
JOIN people ON sent_email_v2s.person_id = people.id
JOIN sequences on sent_email_v2s.sequence_id = sequences.id
JOIN users ON sent_email_v2s.user_id = users.id
WHERE "sent_email_v2s"."status" = 1
AND "people"."person_type" = 0
AND (sent_email_v2s.sequence_id = 1888) AND "users"."team_id" = 1
当我在此查询上运行EXPLAIN ANALYZE时,结果为:
编辑:
今天的结果与我的预期相同。然而,当我昨晚运行时,包含时间戳过滤器所产生的差异大约慢100倍(0.5秒 - > 59秒)。昨晚的EXPLAIN ANALYZE显示所有时间的增加都归因于上面查询计划中的第一个唯一/排序操作。
这里会出现某种缓存问题吗?我现在担心可能会有其他事情(暂时)可能使此查询花费100倍的时间,因为它至少发生过一次。
任何想法都表示赞赏!