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			| Performance tuning  [message #394424] | Fri, 27 March 2009 00:47  |  
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					| avrillavinge Messages: 98
 Registered: July 2007
 | Member |  |  |  
	| I want to tune a SQL server query that has around 5 UNIONALL . Within every union all there are 3subqueries.Query is very big and gets data for 12 months for 5different Applications.  I want to know apart from changing anything in query what can be done to improve perfoemnace |  
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			| Re: Performance tuning  [message #394462 is a reply to message #394424] | Fri, 27 March 2009 04:44   |  
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					| avrillavinge Messages: 98
 Registered: July 2007
 | Member |  |  |  
	| can iu get some inputs on how to tune this query so that i can make modifications using sql server syntax . 
 request you all to pint out teh mistakes so that i can increase teh performance of this query
 
 
 
 
 
 Select TOP 12
 'icd_Rec' As Rec_Type,
 'S11' AS CATG,
 Lastdate1,
 Date_End,
 Count1
 From
 (Select 'icd_Rec' As Rec_Type,
 (CASE WHEN TKNAME IN ('S11-TD-TWD','S11-TD-TWD-sfw')
 THEN 'S11'
 ELSE ' ' END) AS CATG
 ,REPLACE(RIGHT(CONVERT(VARCHAR(11), IR.Date_End, 106),
  , ' ', '-') AS Lastdate1 ,CONVERT(CHAR(6),IR.Date_End, 112) AS Date_End
 ,Count(Reg_ID) As Count1
 FROM dbo.vsrdt_ttp_dt_comp IR
 WHERE
 Status ='Closed'
 AND PRT_ID is NULL
 AND TKNAME IN ('S11-TD-TWD','S11-TD-TWD-sfw')
 AND Date_End Between dateadd(mm,-12,getdate()) and getdate()
 
 
 group by
 (cASE WHEN TKNAME IN ('S11-TD','S11-sfw')
 THEN 'S11'
 ELSE ' ' END)
 ,REPLACE(RIGHT(CONVERT(VARCHAR(11), IR.Date_End, 106),
  , ' ', '-') ,CONVERT(CHAR(6),IR.Date_End, 112)) a
 Order by Date_End
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			| Re: Performance tuning  [message #394464 is a reply to message #394462] | Fri, 27 March 2009 04:54   |  
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					| cookiemonster Messages: 13973
 Registered: September 2008
 Location: Rainy Manchester
 | Senior Member |  |  |  
	| | avrillavinge wrote on Fri, 27 March 2009 09:44 |  | can iu get some inputs on how to tune this query so that i can make modifications using sql server syntax . 
 request you all to pint out teh mistakes so that i can increase teh performance of this query
 
 
 
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 While I can see several mistakes in those two sentences (proof read your messages before posting please) I can't see any in the query, but then I don't know what to look for.
 
 Oracle works differently to sql server, especially top n queries.
 Changes that would make an oracle version of this query faster could make the sqlserver version slower.
 You need to post this in a sqlserver forum.
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			| Re: Performance tuning  [message #394465 is a reply to message #394424] | Fri, 27 March 2009 04:57  |  
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					| avrillavinge Messages: 98
 Registered: July 2007
 | Member |  |  |  
	| Thanks . 
 I have already posted in sql server forum .
 
 I have worked on oracle hence i was looking for oracle related performance tuning but as u said it varies from DB to Db is agreed.
 
 Alo when i remove teh group by clause teh query runs in 1 sdec and with the group by clause it takes 19 sec.\\
 
 Any thoughts on this !! if any please post
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