aggregate function for median calculation - Mailing list pgsql-general

From Thalis A. Kalfigopoulos
Subject aggregate function for median calculation
Date
Msg-id Pine.LNX.4.21.0106181426130.24987-100000@aluminum.cs.pitt.edu
Whole thread Raw
Responses Re: aggregate function for median calculation
Re: aggregate function for median calculation
List pgsql-general
Hippl,
    I'm interested in calculating the median of a set of numbers. The algorithm requires that all values are known in
advance(ie stored in an array). So the question is: how can I store everything first in an array so I can later process
itgiven that I'd like this to be an aggregate function. I thought of creating an aggregate function and have the
state_function()gather all the values of a group in an array and the final_function() to do the actuall median
calculationon this array. But the intermmediate state cannot hold multiple values in an array (can it?)  
Any ideas on how to go with this?

TIA,
thalis


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