Re: record identical operator

On 2013-09-13 19:20:11 -0700, Kevin Grittner wrote:
> Andres Freund <andres@2ndquadrant.com> wrote:
> 
> > Not one that's dependendant on padding bytes, null bitmaps that
> > can or cannot be present and such.
> 
> Can you provide an example of where that's an issue with this
> patch?

I haven't yet tested your patch, but what I am talking about is that
e.g.: SELECT (ARRAY[1,2,3,NULL])[1:3] = ARRAY[1,2,3];
obviously should be true. But both arrays don't have the same binary
representation since the former has a null bitmap, the latter not.
So, if you had a composite type like (int4[]) and would compare that
without invoking operators you'd return something false in some cases
because of the null bitmaps.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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