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Re: NULL != text ?

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On Thu, Oct 20, 2005 at 03:57:41PM +0900, Michael Glaesemann wrote:
> On Oct 20, 2005, at 15:44 , Michael Fuhr wrote:
> >  expression IS DISTINCT FROM expression
> >
> >  For non-null inputs this is the same as the <> operator.  However,
> >  when both inputs are null it will return false, and when just one
> >  input is null it will return true.  Thus it effectively acts as
> >  though null were a normal data value, rather than "unknown".
> 
> Interesting! Thanks, Michael. You don't happen to know off the top of  
> your head if that's standard SQL, do you?

IS DISTINCT FROM is defined in SQL:1999 and SQL:2003.

-- 
Michael Fuhr

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TIP 9: In versions below 8.0, the planner will ignore your desire to
       choose an index scan if your joining column's datatypes do not
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