On Fri, 22 May 2009 17:48:44 +1000 "Michael Harris" <michael.harris@xxxxxxxxxxxx> wrote: > 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? Isn't it a job for group by? select count(*), myvalue from table group by myvalue order by count(*) desc limit 1; -- Ivan Sergio Borgonovo http://www.webthatworks.it -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
