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ugh3012
Yak Posting Veteran
62 Posts |
 Posted - 2013-07-17 : 10:12:43
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Sometime I see nolock in some of the T-SQLs at work. Is that really necessary in terms of performance?...FROM TBl1 INNER JOIN TBL2 (nolock) on TBl1.id = TBl2.id |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
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ugh3012
Yak Posting Veteran
62 Posts |
Posted - 2013-07-17 : 11:44:46
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| This will be fine on our day old SQL Server. Everynight, all information is copied to day old server from production server. That serves as our reporting tool. Once again, thanks. |
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visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2013-07-17 : 11:56:23
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| WelcomeIf data is rather non-volatile then NOLOCK usage is fine as in OLAP systems------------------------------------------------------------------------------------------------------SQL Server MVPhttp://visakhm.blogspot.com/https://www.facebook.com/VmBlogs |
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LoztInSpace
Aged Yak Warrior
940 Posts |
Posted - 2013-07-17 : 15:53:44
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| If data is non-volatile then you don't get any benefit to using NOLOCK anyway.Personally I'd steer clear of it so you don't get into the habit of using it. It's just a bad practice. |
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mfemenel
Professor Frink
1421 Posts |
Posted - 2013-07-17 : 16:10:44
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| While there are some valid cases, more often then not, when I see nolock I think that the developers got themselves into trouble and started having to resort to query hints to keep from shooting themselves in the foot.Mike"oh, that monkey is going to pay" |
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LoztInSpace
Aged Yak Warrior
940 Posts |
Posted - 2013-07-17 : 18:18:53
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| I guess for approximate counts and stuff like that, perhaps it's acceptable but generally they can generally wait on the odd lock as well.You'd have to have a pretty big hole in your foot before you get to the "This is so broken I will accept incorrect data over what I have now" stage! |
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No Lock