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SQL Performance issue

Posted on 2013-05-11
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Last Modified: 2013-05-15
I have 2 environment say A &  B. A  is the testing phrase 1 environment and B is testing phrase 2 env.

In A env I have database which holds more data than env B. When I run a select query on Env A it get's executed fast(say 40 seconds.)Same query executing on env B takes 50 minutes.

Result of this query doesn't return any records.It will be 0.
The select query has 15 joins.No aggregation/calculation is performed in this query. It's just selecting a columns.

1.Below are my analysis details:
I saw the execution plan on both ENV.
In A estimated number & actual number of rows is 0 
In B estimated number = ~76 millions & actual number of rows is 0 

2.Fragmentation:
In env a= ~0.99 for all 15 tables
In env b = ~ 14 for all 15 tables

3.Same query executing without where clause in B is taking just 1 minute.

Should I update the statistics? 

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7 Comments
 
LVL 23

Accepted Solution

by:
Racim BOUDJAKDJI earned 500 total points
ID: 39158379
Please post the show plan.  It looks you are missing an index.  Posting the query would help.  updating statistics and index rebuild can not hurt.  Just make sure you do it at the right time.
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LVL 5

Author Comment

by:VIVEKANANDHAN_PERIASAMY
ID: 39158410
Sorry,Right now I in home and couldn't help to post the plan.

But I confirm that,both has same indexes I missed to mention this point while posting.

Just trying to understand why estimated rows is high for env B.
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LVL 75

Expert Comment

by:Anthony Perkins
ID: 39158770
Just trying to understand why estimated rows is high for env B.
When was the last time statistics were updated?
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LVL 12

Expert Comment

by:Saurabh Bhadauria
ID: 39158947
Two things you can try to updating your statistics ..
Another optimize your query , it may help as the same can behave differently in different environment as per data volume...
And chk out your indexes...
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LVL 5

Author Comment

by:VIVEKANANDHAN_PERIASAMY
ID: 39159086
My concerns here, env having large number of records executes fast ( less than minute) and environment having less records taking long time (morethan 50 minutes). Both output are the same,both have same number of indexes.

I have just like know why the estimated number of records is high(~75 million) in one and 0 in another.So like to understand what is happening inside the database engine.
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LVL 75

Expert Comment

by:Anthony Perkins
ID: 39159656
I have just like know why the estimated number of records is high(~75 million) in one and 0 in another.
Let's try that again, as you may have overlooked my comment:
When was the last time statistics were updated?

Let me know if you do not understand the relevance of the question and why it may address your specific question.
0
 
LVL 5

Author Comment

by:VIVEKANANDHAN_PERIASAMY
ID: 39163715
>>Should I update the statistics? <<

Running sp_updatestats fixed the issue.
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