On 03/16/2015 02:57 PM, Israel Brewster wrote:
I have a table with two timestamp columns for the start time and end time of each record (call them start and end).I'm trying to figure out if there is a way to group these records by "hour of day", that is the record should be included in the group if the hour of the day for the group falls anywhere in the range [start,end]. Obviously each record may well fall into multiple groups under this scenario.The goal here is to figure out, for each hour of the day, a) what is the total number of "active" records for that hour, and b) what is the total "active" time for those records during the hour, with an ultimate goal of figuring out the average active time per record per hour. So, for simplified example, if the table contained three records: start | end ----------------------------------------------------- 2015-03-15 08:15 | 2015-03-15 10:45 2015-03-15 09:30 | 2015-03-15 10:15 2015-03-15 10:30 | 2015-03-15 11:30 Then the results should break out something like this: hour | count | sum ----------------------------- 8 | 1 | 0.75 9 | 2 | 1.5 10 | 3 | 1.5 11 | 1 | 0.5 I can then easily manipulate these values to get my ultimate goal of the average, which would of course always be less than or equal to 1. Is this doable in postgress? Or would it be a better idea to simply pull the raw data and post-process in code? Thanks.
Do not have an answer for you, but a question: What version of Postgres are you on? This will help determine what tools are available to work with.
----------------------------------------------- Israel Brewster Systems Analyst II Ravn Alaska 5245 Airport Industrial Rd Fairbanks, AK 99709 (907) 450-7293 -----------------------------------------------
-- Adrian Klaver adrian.kla...@aklaver.com -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
