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From Edward Capriolo <>
Subject Re: Hive equivalent of group_concat() ?
Date Fri, 11 May 2012 20:05:54 GMT
The main issue with group_concat is that aggregates have to keep each
column in memory and that is a big problem. If The user knows the list
will be small you could write a UDAF like collectset, collect which
puts each value into a list and then you can lateral view that list.


On Fri, May 11, 2012 at 4:02 PM, Saurabh S <> wrote:
> As far as I understand, there is no equivalent of MySQL group_concat() in Hive. This
stackoverflow question is from Sept 2010:
> Does anyone know any other method to create a delimited list from from table rows? There
are a few methods listed in Anthony Molinaro's SQL Cookbook, but all of them use over(partition
by) method which is also not available in Hive.

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