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simple query run very slow

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mahmood.p52
Starting Member

2 Posts

Posted - 2014-12-19 : 16:20:34

hi to all
i use sql 2012 in my application
one or more of tables go very slow in simple query.
i rebuild index but not change.
just when i create a new table and insert from old table to new
it will be normal and fast

tkizer
Almighty SQL Goddess

38200 Posts

Posted - 2014-12-19 : 16:27:13

Show us the query and the showplan xml for it. I would bet you are either missing an index or have out-of-date statistics. We need more info to help.

Tara Kizer
SQL Server MVP since 2007
http://weblogs.sqlteam.com/tarad/

mahmood.p52
Starting Member

2 Posts

Posted - 2014-12-19 : 16:37:33

select * from a where field1 in (
select field2 from b)
and field2='string'

in this query i have a index on field1,field2 on table a
and index on field2 on table b

i tested every thing that you may think .
for example i drop the index and recreate the index but not change.
but recreate a new table and export the data was the solution.
i do not know why it appear

tkizer
Almighty SQL Goddess

38200 Posts

Posted - 2014-12-19 : 16:43:40

We would need to see the showplan xml when the issue occurs again. I might have tried field2,field1 on a. I'd also not use * and would make the index covering.

select *
from a
join b on a.field1 = b.field2
where b.field2 = 'string'

Tara Kizer
SQL Server MVP since 2007
http://weblogs.sqlteam.com/tarad/

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