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In my previous post “ Denali Paging – is it win.win ? ” I demonstrated the use of using the Paging functionality within Denali. On reflection, I think i may of been a little unfair and should of continued always planned to continue my investigations...
I'm not one for automatically poo-pooing new ideas, new practices and new technology. Rather I like to take a measured view and try to evaluate based upon merits. One of the new features in Denali is paging which is now supported by the FETCH option...
Greg Gonzalez ( blog | twitter ) of SqlSentry , last night released a very cool new and free product. Plan explorer is a tool for examining query plans and overcomes many of the limitations of viewing plans within Management studio. If you...
In a previous blog entry ( Inconsistent NullIf behaviour ), Jeff Moden and Dan Halliday ( twitter ) both made a very similar observation. When executing this code Code Snippet select top ( 10 ) abs ( checksum ( newid ()))% 4 from sys . objects the only...
NullIf can be a very handy function sometimes. For those who have not used it, if the result of the two parameters are equal then null is returned. So if we execute : Code Snippet Select nullif ( 10 , 10 ) as Result1 Select nullif ( 10 , 9 ) as Result2...
I am somewhat uncomfortable blogging this, as I feel that it falls into “Polish a turd” category. Having said that, it is a particularly ugly turd and it does polish up rather well. Though as the saying goes, it is still a turd. The evils and inadequacies...
It’s as simple as that. If you don’t specify ORDER BY, then the order of your result set is not guaranteed. Oh sure , there may be situations where the data looks like it is being returned ordered, but this is not really the case. So, for example : CREATE...
I have received a number of requests for an explanation of my winning query of TSQL Challenge 19 . This involved traversing a hierarchy of employees and rolling a count of orders from subordinates up to superiors. The first concept I shall address is...
In SQL2005 (9.00.4207.00), if you use a ranking function within a view or CTE, then an inefficient query plan can be produced. First off in Adventure works create this index Create Index idxLastName on Person . Contact ( LastName ) and then consider these...
As the saying goes "work smarter, not harder", this is definitely the case for SQL. If you have a poorly performing query, then you are not only affecting that one user but diverting precious machine resources needlessly. This is doubly true...