how to put nolock with tabel alies

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how to put nolock with tabel alies

rajemessage 14195

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August 6, 2016 at 4:30 am

#315958

hi,
which one is good way of putting nolock
other think is
Omitting the WITH keyword is a deprecated feature: This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature.
above was given in https://msdn.microsoft.com/en-us/library/ms187373.aspx
is it applicable to single hints also.
1) select * from customer cus(nolock)
join salesorder s(nolock) on cus.custid = s.custid
2) select * from customer(nolock) cus
join salesorder(nolock) s on cus.custid = s.custid
yours sincerley

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The Dixie Flatline SSC Guru Points: 53354 More actions · Answer 1

Answer withdrawn because I prefer not to help people with interview questions.

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Eirikur Eiriksson SSC Guru Points: 182920 More actions · Answer 2

rajemessage 14195 (8/6/2016)
hi,
which one is good way of putting nolock
other think is
Omitting the WITH keyword is a deprecated feature: This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature.
above was given in https://msdn.microsoft.com/en-us/library/ms187373.aspx
is it applicable to single hints also.
1) select * from customer cus(nolock)
join salesorder s(nolock) on cus.custid = s.custid
2) select * from customer(nolock) cus
join salesorder(nolock) s on cus.custid = s.custid
yours sincerley

My question is why use nolock? Do you understand what it means?

😎

Jeff Moden SSC Guru Points: 1004436 More actions · Answer 3

rajemessage 14195 (8/6/2016)
hi,
which one is good way of putting nolock
other think is
Omitting the WITH keyword is a deprecated feature: This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature.
above was given in https://msdn.microsoft.com/en-us/library/ms187373.aspx
is it applicable to single hints also.
1) select * from customer cus(nolock)
join salesorder s(nolock) on cus.custid = s.custid
2) select * from customer(nolock) cus
join salesorder(nolock) s on cus.custid = s.custid
yours sincerley

Neither. The use of the NOLOCK hint is most stupid and can play hell with data and the application. People use it to try to overcome performance problems that shouldn't exist to begin with.

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

Gail Shaw SSC Guru Points: 1004504 More actions · Answer 4

Talking about interviews, I did one last week. The question that tipped the interview from 'maybe' to 'no' was when I asked about the cause of deadlocks and he replied that deadlocks were caused when multiple people queried the same table without using the nolock hint.

So, if this is an interview question, maybe it's a trick question and you're supposed to react with horror and explain why you'd never use nolock so broadly.

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass