+1 to improve the current windows to support that as well. I was also thinking its better if we can make Windows a top-level element like the tables, so that the same window can we used by many queries, which will improve the performance even more.
Suho On Thu, Oct 10, 2013 at 8:53 PM, Srinath Perera <[email protected]> wrote: > Current we update sliding window per event received > > Most Engines support updating the window in batches (e.g. once every > second for time window, once every 10 messages length window). Also > mentioned in 8 Rules paper of Stonebreaker. Thing is if you have 3 months > window, you are generally OK with 10 mins accuracy. > > I think we should support this as this provide huge performance > improvements (bigger the batch, faster). Reason is following. > > When we define windows, most of the time, we calculate aggregates only. > Those can be calculated on the fly, so we do not need to store the events. > But there is a catch, we need to events to handle when events expire and > remove the values from aggregates. However, if we update only in batches, > then we can keep aggregated value for is batch (e.g. for sum, we can just > keep sum for each batch only). > > We will also need to do this for Distributed CEP in the future. > > -- > ============================ > Srinath Perera, Ph.D. > Director, Research, WSO2 Inc. > Visiting Faculty, University of Moratuwa > Member, Apache Software Foundation > Research Scientist, Lanka Software Foundation > Blog: http://srinathsview.blogspot.com/ > Photos: http://www.flickr.com/photos/hemapani/ > Phone: 0772360902 > -- *S. Suhothayan * Associate Technical Lead, *WSO2 Inc. *http://wso2.com * <http://wso2.com/>* lean . enterprise . middleware *cell: (+94) 779 756 757 | blog: http://suhothayan.blogspot.com/ twitter: http://twitter.com/suhothayan | linked-in: http://lk.linkedin.com/in/suhothayan* * *
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