Re: Aggregate Function to return most common value for a column

Hello

I thing, so the function in C is the best solution. And I thing, so
you can use PostgreSQL functionality inside. Pg support hash arrays
and hashing function too.

regards
Pavel Stehule

2009/5/22 Michael Harris <michael.harris@ericsson.com>:
> Hi Experts,
>
> I want to use an aggregate function that will return the most commonly
> occurring value in a column.
>
> The column consists of VARCHAR(32) values.
>
> Is it possible to construct such an aggregate using PL/PgSql ?
>
> If I was trying to do something like this in Perl I would use a hash
> table to store the values and the number of times each was seen as the
> table was iterated, but PL/PgSql does not seem to have an appropriate
> data type for that?
>
> I don't want to use PL/Perl to avoid the overhead of starting a perl
> interpreter for that.
>
> Do I have to write the function in C maybe?
>
>
> Thanks in advance,
> Regards
> Mike Harris
>
>
> --
> Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-general
>