Thread: PostgreSQL documentation specifies 2-element array for float8_accum but 3-element array expected
PostgreSQL documentation specifies 2-element array for float8_accum but 3-element array expected
From
Disc Magnet
Date:
I was learning how to create my own aggregate functions from http://www.postgresql.org/docs/9.0/static/xaggr.html I copied the avg() example as CREATE TABLE numbers ( value integer ); insert into numbers values (2); insert into numbers values (3); insert into numbers values (4); CREATE AGGREGATE myavg(float8) ( sfunc = float8_accum, stype = float8[], finalfunc = float8_avg, initcond = '{0,0}' ); On trying to run this, I get this error: cdb=# select myavg(value) from numbers; ERROR: float8_accum: expected 3-element float8 array How can I fix this?
Re: PostgreSQL documentation specifies 2-element array for float8_accum but 3-element array expected
From
Merlin Moncure
Date:
On Wed, Mar 23, 2011 at 8:03 AM, Disc Magnet <discmagnet@gmail.com> wrote: > I was learning how to create my own aggregate functions from > http://www.postgresql.org/docs/9.0/static/xaggr.html > > I copied the avg() example as > > CREATE TABLE numbers ( > value integer > ); > > insert into numbers values (2); > insert into numbers values (3); > insert into numbers values (4); > > CREATE AGGREGATE myavg(float8) ( > sfunc = float8_accum, > stype = float8[], > finalfunc = float8_avg, > initcond = '{0,0}' > ); > > On trying to run this, I get this error: > > cdb=# select myavg(value) from numbers; > ERROR: float8_accum: expected 3-element float8 array > > How can I fix this? how embarrassing -- the initcont should be: '{0,0,0}' :^). merlin
Re: PostgreSQL documentation specifies 2-element array for float8_accum but 3-element array expected
From
Tom Lane
Date:
Disc Magnet <discmagnet@gmail.com> writes:
> CREATE AGGREGATE myavg(float8) (
> sfunc = float8_accum,
> stype = float8[],
> finalfunc = float8_avg,
> initcond = '{0,0}'
> );
> On trying to run this, I get this error:
> cdb=# select myavg(value) from numbers;
> ERROR: float8_accum: expected 3-element float8 array
Hm, it looks like that example has been wrong from day one ---
float8_accum has expected a 3-element array for its entire existence.
I thought maybe the code and docs had gotten out of sync later, but
AFAICS this was a thinko in the original commit. Should say
initcond = '{0,0,0}'
regards, tom lane