Local-Global Aggregation
Today's topic is a general primer on something that is called "local-global aggregation". Effectively, this is a technique to allow you to take a query containing joins and group bys and perform the group by partially "before" the joins. This can dramatically reduce the number of rows that a query has to process to return a result, and therefore it is a very powerful operation. This technique is also quite useful to split a grouping operation into something that can be done in parallel. That obviously can also speed your query as well.
I hope to put something more formal together soon, work permitting, but here is an introduction that you can read in the meantime:
https://citeseer.ist.psu.edu/jaedicke97framework.html
Thanks,
Conor
Comments
Anonymous
April 21, 2006
Here is what happened this week:
Comparison of XSLT 2.0 and XQuery 1.0
Upcoming WPF/E Channel 9 Video...Anonymous
September 25, 2006
Since we’re starting a new blog for the whole query processing team, we think it’s appropriate to start...Anonymous
September 25, 2006
Since we’re starting a new blog for the whole query processing team, we think it’s appropriate to start...Anonymous
January 04, 2009
Blog Spotlight - April 15 to 21Anonymous
May 31, 2009
PingBack from http://woodtvstand.info/story.php?id=8303