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How to avoid LIKE clause in join - sql server

Hi All,

In the below query, update statment is taking very long time to generate output. Please advise how to rewrite below query for better performance.

I don't want to remove '[' and ']' symbol in query because in the DB data contains '[' and ']' symbols.

CREATE TABLE #temp
(

[Inquiry Number] NVARCHAR(255),
[CPO Number] VARCHAR(50),
[SO Number] VARCHAR(50)
)

CREATE nonclustered INDEX ix_InqNum ON #temp ([Inquiry Number]) include ([CPO Number])

INSERT INTO #temp
(
	[Inquiry Number],[CPO Number]
)

SELECT distinct PRA.inq_num,[PO Number]
FROM [LocalDB].dbo.ps_requests_asr PRA with(nolock)left join [RemoteDB].[DBName].dbo.CPOA with(nolock) ON cast(Inquiries as NVARCHAR(450)) = '[' + PRA.inq_num + ']' 
WHERE PRA.inq_num is not null

UPDATE	#temp SET [SO Number]= CUST.[SO] FROM #temp INNER JOIN [RemoteDB].[DBName].dbo.CPOA CPON WITH(NOLOCK) ON cast(CPON.Inquiries as NVARCHAR(450)) = '[' + #temp.[Inquiry Number] + ']'    	
		INNER JOIN [RemoteDB].[DBName].dbo.BI_CUSTMON CUST WITH(NOLOCK) ON CUST.[Customer PO] LIKE #temp.[CPO Number] + '%'
		
select * from #temp

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HugoHiasl

If you do insert the [ and ] in the insert to the temp table and remove it from the join then the join can use your index which is useless at the moment.

INSERT INTO #temp
(
	[Inquiry Number],[CPO Number]
)
SELECT distinct '['+PRA.inq_num+']',[PO Number]

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and

UPDATE	#temp SET [SO Number]= CUST.[SO] FROM #temp INNER JOIN [RemoteDB].[DBName].dbo.CPOA CPON WITH(NOLOCK) ON cast(CPON.Inquiries as NVARCHAR(450)) = #temp.[Inquiry Number]    	
		INNER JOIN [RemoteDB].[DBName].dbo.BI_CUSTMON CUST WITH(NOLOCK) ON CUST.[Customer PO] LIKE #temp.[CPO Number] + '%'

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And when you are doing changes don't forget to create an index on [CPO Number] of #temp also. Since your join to cpo number is a "starts with" it can also use an index.

sqldba2013

ASKER

I have already created non-clustered index on CPO number of #temp table.

I am facing query slowness issue with UPDATE statement not with INSERT.

Could you please tell me how to avoid like statement in above update statement or how to rewrite above query for better performance.

I have tried with = operator in place of like and I didn't get data as per my requirement for = operator.

Please advise.

sqldba2013

ASKER

As per your suggestion, I have removed [ and ] from join and I got NULL as a output result.

CREATE TABLE #temp
(

[Inquiry Number] NVARCHAR(255),
[CPO Number] VARCHAR(50),
[SO Number] VARCHAR(50)
)

CREATE nonclustered INDEX ix_InqNum ON #temp ([Inquiry Number]) include ([CPO Number])

INSERT INTO #temp
(
	[Inquiry Number],[CPO Number]
)

SELECT distinct '['+PRA.inq_num+']',[PO Number]
FROM [LocalDB].dbo.ps_requests_asr PRA with(nolock)left join [RemoteDB].[DBName].dbo.CPOA with(nolock) ON cast(Inquiries as NVARCHAR(450)) = PRA.inq_num 
WHERE PRA.inq_num is not null

UPDATE	#temp SET [SO Number]= CUST.[SO] FROM #temp INNER JOIN [RemoteDB].[DBName].dbo.CPOA CPON WITH(NOLOCK) ON cast(CPON.Inquiries as NVARCHAR(450)) = #temp.[Inquiry Number]
		INNER JOIN [RemoteDB].[DBName].dbo.BI_CUSTMON CUST WITH(NOLOCK) ON CUST.[Customer PO] LIKE #temp.[CPO Number] + '%'
		
select * from #temp

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SOLUTION