|
Comments
|
|
Finally! a catchy learning experience
|
|
Marc Moshman on
6/23/2009
Why are there two union operations (1004 and 1005) ?
|
|
Steve Harris on
6/23/2009
was good but seemed incomplete. wanting more information.
|
|
|
waste of time
|
|
|
More in depth vids. regarding optimizing execution plans please!
|
|
Sara Karasik on
6/23/2009
Clear, but too elementary. Good for a real beginner, or introductory course.
|
|
Ahmad Elayyan on
6/23/2009
good
|
|
|
I am always up for learning new things about SQL.
|
|
|
Voice not a clear and it would be explined in much better way
|
|
|
Marc Moshman: The two defined values, 1004 and 1005, represent the two columns being unioned together.
|
|
|
Sara Karasik: It was billed as a 100 level information, very basic. The goal on these little videos is just to provide enough information for people learning this stuff to understand a single topic. More advanced videos will need to be created.
|
|
Jamshid Nouri on
6/23/2009
excellent
|
|
|
great video
|
|
|
Pretty short--could expand more by discussing relative tradeoff between doing a Union or solving the problem using other techniques.
|
|
Tim Patterson on
6/24/2009
I like how this guys videos are succinct.
|
|
|
I assume if this a performance issue, we should use UNION ALL and maybe a rownumber() to remove duplicates afterwards if only want distinct rows ?
|
|
|
Gautam, you can, but you may just need to do a UNION. It really depends on the situation.
|
|
|
Very Short
|
|
|
It would have been helpful if you more explanation was provided about the Distinct Sort operator and how to avoid or minimise the cost of that operator.
|
|
|
Why is there a Distinct Sort operator as part of the UNION? Does UNION remove duplicate rows from the combined data set?
|
|
|
UNION removes duplicates. UNION ALL does not. Frequently what's needed is UNION ALL. Using this will remove the need for an aggregate operation. The aggregate is occurring here just as it would in a DISTINCT or GROUP BY situation... it's eliminating the duplicate values.
|
|
|
Want more and longer videos from 'The Scary DBA', please!
|
|
Robert Schmehl on
10/16/2009
to short
|
|
|
Very comprehensive, very helpful. Thank you...
|
|
|
SQLShare is the best info site I have ever visited, and this video is a prime example why: no fluff, no all-encompassing definitions like a crash course, just a quick, to-the-point "cause and effect" type of explanation on a single piece of a single subject. My time of study/learned skill ratio is highest at SQLShare than any other, and videos like this are why.
|
|
|
Great little video. Keep 'em coming.
|
|
|
Many thanks. It would be good to know how that information would be useful in writing queries i.e. is there an alternative way of of writing this query to achieve the same result?
|
|
|
It is already repeated 1 million times.!!!
|
|
|
May have been good to compare union to union all (focusing on [sort distinct]).
|
|
|
good video
|
|
|
Please juxtapose this against a UNION ALL in a single video,showing data samples. You can also show how it performs as compared to a join in certain scenarios.
Nice Video, keep up the good work.
|
|
|
Would definitely have benefited from having a comparison with the Union All operator, especially given how short the video was.
|
|
|
great teacher
|