> -----Original Message----- > From: Erwien Samantha Y [mailto:[EMAIL PROTECTED] > 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. ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html