Viewing 15 posts - 35,341 through 35,355 (of 49,552 total)
Sourav-657741 (12/11/2009)
Hello ExpertsI need a quick response from you guys.
Please start a new thread for a new question rather than hijacking someone else's thread.
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
December 11, 2009 at 9:01 am
Estimated might differ from actual if variables are in use rather than parameters. Because the optimiser can't sniff the value of variables, it has to guess as to cardinality. The...
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
December 11, 2009 at 8:53 am
BobMcC (12/11/2009)
Woah. Most resources say to assign parameters to local variables to avoid parameter sniffing. Now doing that is wrong too?
😀 You asked for it....
It depends.
Seriously, sometimes using variables...
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
December 11, 2009 at 5:30 am
Parameter sniffing - http://sqlinthewild.co.za/index.php/2007/11/27/parameter-sniffing/
(it's a 3-part blog series)
By using variables, you've got a different form of parameter sniffing, more accurately, a lack thereof. The optimiser can't see the value of...
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
December 10, 2009 at 11:34 pm
Please don't cross post. It just wastes peoples time and fragments replies.
No replies to this thread please. Direct replies to: http://www.sqlservercentral.com/Forums/Topic832644-162-1.aspx
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
December 10, 2009 at 11:31 pm
Can you please post the execution plan itself, rather than just a screenshot? There's a lot of info that a single screenshot can't show.
http://www.sqlservercentral.com/articles/SQLServerCentral/66909/
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
December 10, 2009 at 11:31 pm
Maybe. 😉
Try it and see. If queries use it, then it's a useful index. If they don't then drop it. I'd say if it's very selective for some queries (<1%...
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
December 10, 2009 at 11:27 pm
SQL doesn't consistently do position-based short circuiting. It can eliminate obvious contradictions, however there's another thing to consider. The execution plans will be cached for reuse. One rule that SQL...
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
December 10, 2009 at 1:01 pm
Seeing as this is SQL 2008, why not just use the built-in geometry data type and one of the built-in geometry functions that can calculate whether a point is inside...
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
December 10, 2009 at 12:50 pm
Alvin Ramard (12/10/2009)
And here at SCC there are too many who think they know everything and give those of us who do a bad name.
Not just at SSC. Am currently...
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
December 10, 2009 at 12:48 pm
I'm guessing you didn't read the article.
Table definitions and sample data?
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
December 10, 2009 at 12:41 pm
jparks-1090949 (12/10/2009)
Made updates to a table (SQL Server 2005)Would like to rollback those changes
Only possible if you made the changes inside an explicit transaction and haven't run COMMIT...
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
December 10, 2009 at 11:12 am
Firstly learn how to do ANSI joins. Then, to get the blank rows, use outer joins instead of inner joins;.
SELECT table1.column1, table2.column1, table2.column2
FROM table1
...
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
December 10, 2009 at 11:09 am
Please post table definitions, sample data and desired output. Read this to see the best way to post this to get quick responses.
http://www.sqlservercentral.com/articles/Best+Practices/61537/
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
December 10, 2009 at 10:56 am
jcrawf02 (12/10/2009)
Gail's being subtle again - I'd be SOM if I were drinking anything :hehe:
I'm losing my temper with him. And that takes some doing these days.
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
December 10, 2009 at 10:53 am
Viewing 15 posts - 35,341 through 35,355 (of 49,552 total)