超级慢查询-加快了速度,但并不完美...请帮助 [英] Super Slow Query - sped up, but not perfect... Please help
问题描述
我昨天发布了一个查询(请参见此处)那太可怕了(花了一分钟时间,导致18,215条记录):
I posted a query yesterday (see here) that was horrible (took over a minute to run, resulting in 18,215 records):
SELECT DISTINCT
dbo.contacts_link_emails.Email, dbo.contacts.ContactID, dbo.contacts.First AS ContactFirstName, dbo.contacts.Last AS ContactLastName, dbo.contacts.InstitutionID,
dbo.institutionswithzipcodesadditional.CountyID, dbo.institutionswithzipcodesadditional.StateID, dbo.institutionswithzipcodesadditional.DistrictID
FROM
dbo.contacts_def_jobfunctions AS contacts_def_jobfunctions_3
INNER JOIN
dbo.contacts
INNER JOIN
dbo.contacts_link_emails
ON dbo.contacts.ContactID = dbo.contacts_link_emails.ContactID
ON contacts_def_jobfunctions_3.JobID = dbo.contacts.JobTitle
INNER JOIN
dbo.institutionswithzipcodesadditional
ON dbo.contacts.InstitutionID = dbo.institutionswithzipcodesadditional.InstitutionID
LEFT OUTER JOIN
dbo.contacts_def_jobfunctions
INNER JOIN
dbo.contacts_link_jobfunctions
ON dbo.contacts_def_jobfunctions.JobID = dbo.contacts_link_jobfunctions.JobID
ON dbo.contacts.ContactID = dbo.contacts_link_jobfunctions.ContactID
WHERE
(dbo.contacts.JobTitle IN
(SELECT JobID
FROM dbo.contacts_def_jobfunctions AS contacts_def_jobfunctions_1
WHERE (ParentJobID <> '1841')))
AND
(dbo.contacts_link_emails.Email NOT IN
(SELECT EmailAddress
FROM dbo.newsletterremovelist))
OR
(dbo.contacts_link_jobfunctions.JobID IN
(SELECT JobID
FROM dbo.contacts_def_jobfunctions AS contacts_def_jobfunctions_2
WHERE (ParentJobID <> '1841')))
AND
(dbo.contacts_link_emails.Email NOT IN
(SELECT EmailAddress
FROM dbo.newsletterremovelist AS newsletterremovelist))
ORDER BY EMAIL
经过大量的指导和研究,我将其调整为以下内容:
With a lot of coaching and research, I've tuned it up to the following:
SELECT contacts.ContactID,
contacts.InstitutionID,
contacts.First,
contacts.Last,
institutionswithzipcodesadditional.CountyID,
institutionswithzipcodesadditional.StateID,
institutionswithzipcodesadditional.DistrictID
FROM contacts
INNER JOIN contacts_link_emails ON
contacts.ContactID = contacts_link_emails.ContactID
INNER JOIN institutionswithzipcodesadditional ON
contacts.InstitutionID = institutionswithzipcodesadditional.InstitutionID
WHERE
(contacts.ContactID IN
(SELECT contacts_2.ContactID
FROM contacts AS contacts_2
INNER JOIN contacts_link_emails AS contacts_link_emails_2 ON
contacts_2.ContactID = contacts_link_emails_2.ContactID
LEFT OUTER JOIN contacts_def_jobfunctions ON
contacts_2.JobTitle = contacts_def_jobfunctions.JobID
RIGHT OUTER JOIN newsletterremovelist ON
contacts_link_emails_2.Email = newsletterremovelist.EmailAddress
WHERE (contacts_def_jobfunctions.ParentJobID <> 1841)
GROUP BY contacts_2.ContactID
UNION
SELECT contacts_1.ContactID
FROM contacts_link_jobfunctions
INNER JOIN contacts_def_jobfunctions AS contacts_def_jobfunctions_1 ON
contacts_link_jobfunctions.JobID = contacts_def_jobfunctions_1.JobID
AND contacts_def_jobfunctions_1.ParentJobID <> 1841
INNER JOIN contacts AS contacts_1 ON
contacts_link_jobfunctions.ContactID = contacts_1.ContactID
INNER JOIN contacts_link_emails AS contacts_link_emails_1 ON
contacts_link_emails_1.ContactID = contacts_1.ContactID
LEFT OUTER JOIN newsletterremovelist AS newsletterremovelist_1 ON
contacts_link_emails_1.Email = newsletterremovelist_1.EmailAddress
GROUP BY contacts_1.ContactID))
虽然此查询现在非常快(大约3秒),但我已经将逻辑的一部分吹散了-它仅返回14,863行(而不是我认为是准确的18,215行).
While this query is now super fast (about 3 seconds), I've blown part of the logic somewhere - it only returns 14,863 rows (instead of the 18,215 rows that I believe is accurate).
结果似乎接近正确.我正在努力寻找结果集中可能缺少的数据.
The results seem near correct. I'm working to discover what data might be missing in the result set.
您能通过我在这里做错的事情来指导我吗?
Can you please coach me through whatever I've done wrong here?
谢谢
罗素·舒特(Russell Schutte)
Russell Schutte
推荐答案
原始查询的主要问题是,您有两个额外的联接只是为了引入重复项,然后有一个DISTINCT
来消除它们.
The main problem with your original query was that you had two extra joins just to introduce duplicates and then a DISTINCT
to get rid of them.
使用此:
SELECT cle.Email,
c.ContactID,
c.First AS ContactFirstName,
c.Last AS ContactLastName,
c.InstitutionID,
izip.CountyID,
izip.StateID,
izip.DistrictID
FROM dbo.contacts c
INNER JOIN
dbo.institutionswithzipcodesadditional izip
ON izip.InstitutionID = c.InstitutionID
INNER JOIN
dbo.contacts_link_emails cle
ON cle.ContactID = c.ContactID
WHERE cle.Email NOT IN
(
SELECT EmailAddress
FROM dbo.newsletterremovelist
)
AND EXISTS
(
SELECT NULL
FROM dbo.contacts_def_jobfunctions cdj
WHERE cdj.JobId = c.JobTitle
AND cdj.ParentJobId <> '1841'
UNION ALL
SELECT NULL
FROM dbo.contacts_link_jobfunctions clj
JOIN dbo.contacts_def_jobfunctions cdj
ON cdj.JobID = clj.JobID
WHERE clj.ContactID = c.ContactID
AND cdj.ParentJobId <> '1841'
)
ORDER BY
email
创建以下索引:
newsletterremovelist (EmailAddress)
contacts_link_jobfunctions (ContactID, JobID)
contacts_def_jobfunctions (JobID)
这篇关于超级慢查询-加快了速度,但并不完美...请帮助的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!