SA Developer .NET

Which would be better for performance:

IF @oldVal1 <> @newVal1

OR @oldVal2 <> @newVal2

OR @oldVal3 <> @newVal3

SET @isValueChanged = 1

 

or

IF @oldVal1 <> @newVal1

OR @oldVal2 <> @newVal2

OR @oldVal3 <> @newVal3

SET @isValueChanged = 1

 

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A Program is only Complete when the Programmer Dies

I can't see any difference between the two options you posted.

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Gail Shaw - SQL In the Wild
SQL Server MVP
--
Chaos, panic and disorder. My job here is done!

The one has a beer and the other an angel? ... personally I'd go for the beer

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Why go against tradition when we can admit defeat, live in decline, be the victim of our own design?
http://dotnet.org.za/calmyourself

Lol, I've always had a problem with copying and pasting....after a few beers.

 [ A ]

IF @oldVal1 <> @newVal1

  OR @oldVal2 <> @newVal2

  OR @oldVal3 <> @newVal3

  SET @isValueChanged = 1

or

[ B ]

IF @oldVal1 <> @newVal1

  SET @isValueChanged = 1

IF @oldVal2 <> @newVal2

  SET @isValueChanged = 1

IF @oldVal3 <> @newVal3

  SET @isValueChanged = 1

 

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A Program is only Complete when the Programmer Dies

CalmYourself:

The one has a beer and the other an angel? ... personally I'd go for the beer

I am relying on my years of very technical experience here and I am going to have to say....

The one with the beer next to it is the better option!

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fridgi:

CalmYourself:

The one has a beer and the other an angel? ... personally I'd go for the beer

I am relying on my years of very technical experience here and I am going to have to say....

The one with the beer next to it is the better option!

To hell with technical experience, beer always!!!!

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The Question is the Answer, and the Answer is the Question!

Anyway,

Back to your problem, I'd personally go with option (A). I personally feel you should have as few COF statements as possible.

Unless of course, you have many values to check.. for this example I'd go with (A).

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The Question is the Answer, and the Answer is the Question!

Having just run this scenario through SQL profiler, it seems Profiler registers no difference in whether or not you use (A) or (B). It only registers 14 reads in total.

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The Question is the Answer, and the Answer is the Question!

horatio:

fridgi:

CalmYourself:

The one has a beer and the other an angel? ... personally I'd go for the beer

I am relying on my years of very technical experience here and I am going to have to say....

The one with the beer next to it is the better option!

To hell with technical experience, beer always!!!!

 * Kitten perks up interestedly.

Beer?  When?  Where?  Oh, mistype...

 * Kitten loses interest.

I'd have to say A would be the better option there too...

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Someone once told me love makes the world go around and, well, I just had to laugh in their face because EVERYBODY knows what REALLY makes the world go around is a mutant gerbil on a treadmill.

I'm swayed towards option A cause the value of the variable could potentially be set to itself multiple times in option B.

but, option A can  become untidy over time as more checks are added to the same IF statement.

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A Program is only Complete when the Programmer Dies

NeverDie:

I'm swayed towards option A cause the value of the variable could potentially be set to itself multiple times in option B.

but, option A can  become untidy over time as more checks are added to the same IF statement.

True,

If you foresee the statement could change in the future (requiring a "quick fix"), rather use Option B then. It will be much easier to debug as well if you have a lot of statements.

As I said before, there is no difference in performance, so (B) could do fine.

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The Question is the Answer, and the Answer is the Question!

Well, if there are a lot of condition statements then why not create a SQL function to do this? Wouldn't that be better?

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"I would love to change the world, but they won't give me the source code"
SMS your TO DO list to your email

NeverDie:

Lol, I've always had a problem with copying and pasting....after a few beers.

At 11:00?  Where do you work?  Can I join you? 

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Unscrambling Eggs: Decompiling ASP.NET

NeverDie:

Which would be better for performance:

Generally in SQL, the times you need to worry about performance is when you are accessing data. Shaving a millisecond or two off a comparison is fairly inconsequential if the query takes significantly longer.

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Gail Shaw - SQL In the Wild
SQL Server MVP
--
Chaos, panic and disorder. My job here is done!

Thanks Gila.

I'm finding these days that Processing Power and memory available is not becoming an issue or bottleneck with performance anymore.

You are quite right, the performance is around actually accessing the data. I've seen up to two thousand percent performance gains by just reworking the SQL to access the data better.

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A Program is only Complete when the Programmer Dies