Re: Domains as Subtypes

[elein <elein(at)varlena(dot)com>]

On Mon, Mar 27, 2006 at 11:41:30AM -0500, Tom Lane wrote:
> elein <elein(at)varlena(dot)com> writes:
> > But I like the idea of centralizing the check in the input/output
> > functions.  It seems clearer and cleaner.
> 
> I remembered the problem with doing it that way: an input function can't
> enforce a domain NOTNULL constraint, because it won't even get invoked
> for a null input value.  So there seems no way around having a special
> case for domains in all places where I/O conversion is done.
> 

The notnull attribute of the pg_type table should be set to not null
in the case of a not null constraint on a domain (type).
You should not have to invoke the input function to check for that.  
Or perhaps I'm missing the details.

> 			regards, tom lane
> 
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elein
elein(at)varlena(dot)com