Tuning a plain select statement

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Tuning a plain select statement

sql_butterfly

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February 24, 2011 at 4:27 am

#388928

We have one procedure where after join some tables the records are put into one temporary table (this step is processed fast). Now at the end when we are doing a select statement from that temp table to show data on our frontend, it takes around 10 seconds for mere 1000 records. Can a plain select statement be made faster ?

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vishal.gamji SSCertifiable Points: 6126 More actions · Answer 1

vishal.gamji

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Points: 6126

February 24, 2011 at 7:56 am

#1290999

Can u send your queries pls.

Lowell SSC Guru Points: 323518 More actions · Answer 2

sql_butterfly (2/24/2011)
We have one procedure where after join some tables the records are put into one temporary table (this step is processed fast). Now at the end when we are doing a select statement from that temp table to show data on our frontend, it takes around 10 seconds for mere 1000 records. Can a plain select statement be made faster ?

the devil is in the details...

some hints while we are waiting for more info:

@temp table variables can cause slow results if they contain a lot of records...my rule of thumb is more than 500 records should be in a #temp table and not a table variable

the WHERE statement is where most of the tuning decisions are made. you might even need to index the temp table, ore remove the temp table and use a CTE to get the final results to take advantage of indexes ont he original table.

Lowell

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ChazMan SSCrazy Points: 2259 More actions · Answer 3

I would ask why you need to use a temp table at all. The CTE option described would likely help (but again we need the details.

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Grant Fritchey SSC Guru Points: 398882 More actions · Answer 4

Are you 100% sure the slow part of the process is the select statement? Also, if it's just a straight select, no joins, no where clause, then you're dependent on scanning the temp table and there is no real way to improve a scan.

But as everyone else has said, hard to know without knowing what we're talking about. Execution plans would be good too.

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sql_butterfly Ten Centuries Points: 1264 More actions · Answer 5

Sorry Folks, After investigations we found it was because of rendering at frontend and not backend. Query is doing good.