Re: idea - new aggregates median, listagg - Mailing list pgsql-hackers

From Thom Brown
Subject Re: idea - new aggregates median, listagg
Date
Msg-id bddc86150912160724l3409ae6fua07b905d90ac7d35@mail.gmail.com
Whole thread Raw
In response to idea - new aggregates median, listagg  (Pavel Stehule <pavel.stehule@gmail.com>)
Responses Re: idea - new aggregates median, listagg  (Pavel Stehule <pavel.stehule@gmail.com>)
Re: idea - new aggregates median, listagg  (Scott Bailey <artacus@comcast.net>)
List pgsql-hackers
2009/12/15 Pavel Stehule <pavel.stehule@gmail.com>
Hello

I am looking on new feature - ORDER clause in aggregate, and I thing,
so we are able to effectively implement some non standard, but well
known aggregates.

a) function median - it is relative frequent request - with usually
slow implementation

b) function listagg (it is analogy of group_concat from MySQL) - it
should simplify report generating and some other

What is your opinion? Do you like to see these functions in core?



I'm probably missing the point here, but when I originally saw MySQL's group_concat function, I found it odd that it featured ordering functionality.  Shouldn't the order by determined by the query itself?  Otherwise it's almost as if its separating the relationship between the result column and the resultset.

Thom

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