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Maria90
Starting Member
1 Post |
 Posted - 2009-03-20 : 09:44:19
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| I know the different between searching for an exact string with WHERE COLUMN='X' and the flexible LIKE. I would like to know if WHERE COLUMN='X' is more efficient in searching (faster) than LIKE because it doesn't have the same flexibility. I mean if I am searching for an exact string "testString", wouldn't be any difference to use WHERE or LIKE when it comes to performance?Thanks |
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sakets_2000
Master Smack Fu Yak Hacker
1472 Posts |
Posted - 2009-03-20 : 09:57:01
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| suggest you go thru this,http://www.mssqltips.com/tip.asp?tip=1346 |
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webfred
Master Smack Fu Yak Hacker
8781 Posts |
Posted - 2009-03-20 : 10:13:50
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From: http://bytes.com/groups/ms-sql/159177-like-vs(Erland Sommarskog, SQL Server MVP)It can be virtually difference at all, or it can like night and day.If col is non-indexed, the only overhead is a somewhat more complexcomparison operation.If col is indexed with a non-clustered index, the optimizer will haveto make a decision on whether to use the index. Assume for simplicitythat the index is unique. Then = will use that index, and access will befast. But if there is LIKE there is another story. In this case, thereare two possible strategies: use the index or scan the table. Scanningthe table is better a large proportion of the rows start with 'abc%'.The optimizer does not know about this, but from statistics compiledabout the table, it can make an estimate. If the estimate is incorrect,the plan may not be the best - something the users will very painfullynotice.
No, you're never too old to Yak'n'Roll if you're too young to die. |
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LIKE more efficient than WHERE COLUMN='X'