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cognos79
Posting Yak Master
241 Posts |
 Posted - 2010-09-29 : 23:00:35
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| I do have a table with over 600k records and have a non-clustered index on "course" column.when I do something like select * from table where course is not null sql server is doing a index scan and taking way long time to execute. Is there a way I can speed up the query execution? |
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Sachin.Nand
2937 Posts |
Posted - 2010-09-29 : 23:55:51
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| What are columns in "*"?PBUH |
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cognos79
Posting Yak Master
241 Posts |
Posted - 2010-09-30 : 09:06:05
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| I am just selecting two columns in select list. |
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Transact Charlie
Master Smack Fu Yak Hacker
3451 Posts |
Posted - 2010-09-30 : 09:12:32
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| how selective is that query? (what precentage of rows returned from the whole).If it's a large precentage An index scan could well be the most efficient way to do it.However, it will then have to perform a lookup because you are SELECing *If it's only two columns then you could try INCLUDING the column(s) in your index.Charlie===============================================================Msg 3903, Level 16, State 1, Line 1736The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION |
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query tuning