Re: IS NOT DISTINCT FROM + Indexing - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: IS NOT DISTINCT FROM + Indexing
Date
Msg-id CAM3SWZQrrdTZ-BR9L+rS5ZAxz7_x0Ysijwvc+vj46bLrtK1f+Q@mail.gmail.com
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In response to Re: IS NOT DISTINCT FROM + Indexing  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On Mon, Jul 21, 2014 at 4:57 PM, Andres Freund <andres@anarazel.de> wrote:
> I rather doubt it will. x in (y1, ... yn) is essentially expanded to x =
> y1 OR x = y2, ... OR x = yn. I.e. the NULL comparison will be done using
> normal equality comparison and thus not return a row with a NULL
> orderid. Am I missing something?

I was a little bit incautious in my use of words. The point is that a
scanKey could easily represent a ScalarArrayOpExpr with NULLs and
non-NULLs.
-- 
Peter Geoghegan



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