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aoriju
Posting Yak Master
156 Posts |
 Posted - 2011-11-01 : 07:10:10
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| Why does a covering index improve performance? Choice 1 A covering index is unique. Choice 2 A covering index is clustered. Choice 3 All of the fields in the WHERE and ORDER BY clause are indexed. Choice 4 All tables are joined by primary keys. Choice 5 All the fields in the SELECT list and the WHERE clause are within the index pages. |
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nigelrivett
Master Smack Fu Yak Hacker
3385 Posts |
Posted - 2011-11-01 : 07:13:36
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| Which do you think are not true? How many do you have left that you are unsure about?Do you know what a covering index is?==========================================Cursors are useful if you don't know sql.SSIS can be used in a similar way.Beer is not cold and it isn't fizzy. |
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jassi.singh
Posting Yak Master
122 Posts |
Posted - 2011-11-01 : 07:18:04
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| Improvement is due to the fact that the <b>nonclustered index</b> contained all of the required information to resolve the query. No Key Lookups were required. An index that contains all information required to resolve the query is known as a "Covering Index"; it completely covers the query.Please mark answer as accepted if it helped you.Thanks,Jassi Singh |
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aoriju
Posting Yak Master
156 Posts |
Posted - 2011-11-01 : 07:19:58
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| I am seeking the ans only |
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nigelrivett
Master Smack Fu Yak Hacker
3385 Posts |
Posted - 2011-11-01 : 07:34:35
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| No point really in having the answer if you don't know what it means.Do you know what an index is?==========================================Cursors are useful if you don't know sql.SSIS can be used in a similar way.Beer is not cold and it isn't fizzy. |
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lionofdezert
Aged Yak Warrior
885 Posts |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2011-11-01 : 07:39:26
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quote:
Originally posted by aoriju
I am seeking the ans only
whats the use in just knowing the answer without understanding what it is?------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/ |
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Covering Index