On Jul 27, 2010, at 7:12 PM, Dann Corbit wrote: >> I have a table containing events with timestamps. I would like >> to generate a histogram of the number of each type of event for each >> half-hour period from 8:00 am to 6:00 pm. Are there any tools that >> will help me do this? > > GROUP BY is essentially a histogram generator. > The age() function will give you an interval. > > I am not sure if you want to combine half hour periods from different days > with the same time or not (IOW are 8AM Tuesday and 8AM Wednesday supposed to > be grouped together or not?) > > I guess that if you are more specific about exactly what you want you can get > a better answer. Your requirement is a little bit vague or ambiguous.
I don't mind using Excel to generate the actual graphic. Ideally I'd
get output something like this:
date start end event count
---------- -------- -------- -------- -----
2010-07-27 08:00:00 08:29:59 EVENT_1 20
2010-07-27 08:00:00 08:29:59 EVENT_2 15
2010-07-27 08:30:00 08:59:59 EVENT_1 10
2010-07-27 08:30:00 08:59:59 EVENT_3 5
I'm quite familiar with SQL, but I'm not sure how to generate the half hour
intervals without hard coding them.
Thanks,
Patrick
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