Thread: Re: translator

Re: translator

From
"Dave Page"
Date:

> -----Original Message-----
> From: Erwien Samantha Y [mailto:apache@cosinus.sederhana.or.id]
> Sent: 03 July 2003 17:32
> To: pgadmin-hackers
> Subject: Re: [pgadmin-hackers] translator
>
>
> What is the correct definition of "Cast" and "Aggregate" in PostgreSQL

Off the top of my head:

Cast - A special type of function used to convert from one datatype to
another e.g. int4 -> text. May be used implicitly i.e. PostgreSQL will
automatically use it when required, or explicitly i.e. you write a query
such as SELECT 23::text;

Aggregate - A function (sometimes functions) that return a single result
from a group of values - for example SELECT max(foo) FROM bar; will
return a single value which is the maximum value found in the foo column
in the bar table. Other aggregates include min() (minimum) and avg()
(average).

Regards, Dave.