<a href="http://g.adspeed.net/ad.php?do=clk&zid=15220&wd=468&ht=60&pair=as" target="_blank"><img style="border:0px;" src="http://g.adspeed.net/ad.php?do=img&zid=15220&wd=468&ht=60&pair=as" alt="i" width="468" height="60"/></a>
Log in
::
Register
::
Not logged in
Home
Tags
Articles
Editorials
Stairways
Forums
Scripts
Videos
Blogs
QotD
Books
Ask SSC
SQL Jobs
Training
Authors
About us
Contact us
Newsletters
Write for us
<a href="http://g.adspeed.net/ad.php?do=clk&zid=15491&wd=120&ht=300&pair=as" target="_top"><img style="border:0px;" src="http://g.adspeed.net/ad.php?do=img&zid=15491&wd=120&ht=300&pair=as" alt="i" width="120" height="300"/></a>
Recent Posts
Recent Posts
Popular Topics
Popular Topics
Home
Search
Members
Calendar
Who's On
Home
»
Article Discussions
»
Article Discussions by Author
»
Discuss content posted by Kevin Wu
»
How to Compare Rows within Partitioned Sets...
13 posts, Page 2 of 2
««
1
2
How to Compare Rows within Partitioned Sets to Find Overlapping Dates
Rate Topic
Display Mode
Topic Options
Author
Message
kevin.wu
kevin.wu
Posted Monday, October 11, 2010 10:13 AM
Forum Newbie
Group: General Forum Members
Last Login: Tuesday, April 23, 2013 6:01 PM
Points: 9,
Visits: 319
David McKinney (10/11/2010)
Shouldn't you have a LEFT JOIN rather than an INNER JOIN?
You're right! In haste, I ran an INNER JOIN so that I could just see the compared rows, but in hindsight, I probably should have kept my base table pure and ran a LEFT JOIN instead. This at least would have allowed me to keep my table counts the same as well as singling out the last row in each partitioned set.
Post #1002309
kevin.wu
kevin.wu
Posted Monday, October 11, 2010 10:25 AM
Forum Newbie
Group: General Forum Members
Last Login: Tuesday, April 23, 2013 6:01 PM
Points: 9,
Visits: 319
ta.bu.shi.da.yu (10/11/2010)
If I read this correctly, you just implemented the LAG(...) Over(...) analytic function.
Cool, I didn't even know this existed. But it looks like it's only available in Oracle databases. Microsoft, please bring this over!
However, I'm interested... if you do this on a large dataset, what does the execution plan look like?
Let me try to get my execution plan and I'll get back to you. I do remember that our initial process ran painfully slow and we had just 45K rows. It ran for something like 45 seconds (almost 1 sec/1K rows) using a scalar function. This updated process now takes less than one second to complete.
Post #1002320
k_t_Schmidt
k_t_Schmidt
Posted Tuesday, October 12, 2010 3:53 PM
Grasshopper
Group: General Forum Members
Last Login: Yesterday @ 9:04 AM
Points: 16,
Visits: 107
Real World Example: Wage and Hour Class Action Lawsuits. I am always working with dates on employment cases and many times the individual has many start and end dates. Part of the scrubbing process is to check for date overlaps or gaps. This is a good start to check those types of things.
Thanks for the post! :)
Post #1003261
« Prev Topic
|
Next Topic »
13 posts, Page 2 of 2
««
1
2
Permissions
You
cannot
post new topics.
You
cannot
post topic replies.
You
cannot
post new polls.
You
cannot
post replies to polls.
You
cannot
edit your own topics.
You
cannot
delete your own topics.
You
cannot
edit other topics.
You
cannot
delete other topics.
You
cannot
edit your own posts.
You
cannot
edit other posts.
You
cannot
delete your own posts.
You
cannot
delete other posts.
You
cannot
post events.
You
cannot
edit your own events.
You
cannot
edit other events.
You
cannot
delete your own events.
You
cannot
delete other events.
You
cannot
send private messages.
You
cannot
send emails.
You
may
read topics.
You
cannot
rate topics.
You
cannot
vote within polls.
You
cannot
upload attachments.
You
may
download attachments.
You
cannot
post HTML code.
You
cannot
edit HTML code.
You
cannot
post IFCode.
You
cannot
post JavaScript.
You
cannot
post EmotIcons.
You
cannot
post or upload images.
Copyright © 2002-2013 Simple Talk Publishing. All Rights Reserved.
Privacy Policy.
Terms of Use.
Report Abuse.
