creating a complex type and using it in a table would create the same problem, would it not? If my type has more than one component, then it would not work well.
Here is a better example. Imagine creating a type for complex numbers. Each complex number has 2 components: a real component (x, numeric) and an imaginary component (y, numeric). The standard representation is x +/- yi, so if the real component is 3.4 and the imaginary component is 5, it would be written 3.4 + 5i. Storing this data in the database would require either: 1: A text string which would be parsed by the app. (not really very useful) 2: A native datatype consisting of 2 numeric components, that could be cast as text by the rules above. Obviously the second one is best. Currently in PostgreSQL, I would have to write this in C, but with complex types, I could write this mostly in PLPGSQL! Best Wishes, Chris Travers ----- Original Message ----- From: "Michael Glaesemann" <[EMAIL PROTECTED]> To: "Chris Travers" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; "Tom Lane" <[EMAIL PROTECTED]> Sent: Thursday, January 01, 2004 10:48 PM Subject: Re: [GENERAL] Bug and/or feature? Complex data types in tables... > On Dec 31, 2003, at 7:20 PM, Chris Travers wrote: > > > This concept of using complex types in tables actually does have one > > legitimate use. When used with casts and functions, you could use it > > as a > > "poor-man's datatype" development method. > > > > Here is a hypothetical example. Imagine for a moment that there was > > no CIDR > > datatype. I could create a datatype as a set of ints and then create > > casting functions which I could use for display of the data. This > > would be > > similar to C except that it could be done by people like myself whose C > > coding skills are not up to the level where I or anyone else would > > want them > > in the database backend ;-) > > This is a situation where PostgreSQL's CREATE DOMAIN, or CREATE TYPE > support would be useful, I think. Is there a reason these wouldn't work > as well as using a "table type"? > > Happy New Year! > Michael Glaesemann > grzm myrealbox com > > > ---------------------------(end of broadcast)--------------------------- > TIP 2: you can get off all lists at once with the unregister command > (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED]) > > ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
