Performance issue with my MYSQL query with subqueries - mysql

Question

I have a huge performance issue with my below query I figured that what is the leakage but don't know how to go around it.
the issue is that inner selects go through all the records in tables which is like 200K and then try to select and apply the filter to it so the whole data get selected in the first round.
SELECT *
FROM (
SELECT
( SELECT GROUP_CONCAT(tp.login) login
FROM tp
WHERE tp.user_id = ue.user_id ) login,
u.email as email,
ue.fname as name
FROM user_extra ue
LEFT JOIN users u ON u.id = ue.user_id
) t
WHERE
email like '%sradesign.net#gmail.com%'
OR fname like '%test%'
OR login like '%461988%

Answer 1

Test does I have not made a mistake:
SELECT GROUP_CONCAT(tp.login) login,
u.email as email,
ue.fname as name
FROM user_extra ue
JOIN users u ON u.id = ue.user_id -- I doubt in LEFT
JOIN tp ON tp.user_id = ue.user_id
GROUP BY ue.fname,
u.email
-- , ue.user_id -- maybe needed, but I doubt
HAVING email like '%sradesign.net#gmail.com%'
OR fname like '%test%'
OR login like '%461988%
This is intermediate variant - it must be divided on two (or maybe three - depends on your data) separate queries combined with UNION later.
sometimes it happens that one user doesn't have any login(there is no record for him in tp table) but I want to show him if the customer search term matched in the email of fname how to do this? – Ali Mahmoudi
In such case this table must be joined using outer joining (LEFT JOIN). – Akina
with left join again become like before performance issue the query run for 200 Second – Ali Mahmoudi
As I have said above - this is intermediate variant. If it is correct then let's divide taking into account possible absence in tp:
SELECT GROUP_CONCAT(tp.login) login,
u.email as email,
ue.fname as name
FROM user_extra ue
JOIN users u ON u.id = ue.user_id -- I doubt in LEFT
LEFT JOIN tp ON tp.user_id = ue.user_id
WHERE u.email like '%sradesign.net#gmail.com%'
GROUP BY ue.fname,
u.email
UNION ALL
SELECT GROUP_CONCAT(tp.login) login,
u.email as email,
ue.fname as name
FROM user_extra ue
JOIN users u ON u.id = ue.user_id -- I doubt in LEFT
LEFT JOIN tp ON tp.user_id = ue.user_id
WHERE ue.fname like '%test%'
GROUP BY ue.fname,
u.email
UNION ALL
SELECT GROUP_CONCAT(tp.login) login,
u.email as email,
ue.fname as name
FROM user_extra ue
JOIN users u ON u.id = ue.user_id -- I doubt in LEFT
JOIN tp ON tp.user_id = ue.user_id
GROUP BY ue.fname,
u.email
HAVING login like '%461988%
Test its output for correctness.
If it will produce duplicates then replace UNION ALL with UNION DISTINCT.

Answer 2

You seem to have an extra layer of SELECTs. This causes an extra temp table that contains a huge amount of data.
Unnecessary use of LEFT adds confusion and may prevent some optimizations.
Leading wildcards prevent usage of index.
OR is hard to optimize. But...
A common trick for optimizing OR:
( SELECT ... WHERE email like '%sradesign.net#gmail.com%' )
UNION DISTINCT
( SELECT ... WHERE fname like '%test%' )
UNION DISTINCT
( SELECT ... WHERE login like '%461988% )
However, because of the JOINs, UNION may not be practical.
Consider using FULLTEXT instead of LIKE.