Subject: Re: Testing if an attribute name is in a list of names
From: "Paul A. Hoadley" <paulh@xxxxxxxxxxxxxx>
Date: Fri, 20 May 2005 12:55:06 +0930
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Hi Aron,
On Thu, May 19, 2005 at 01:28:23PM +0000, Aron Bock wrote:
> >if attribute-name is in list-of-attribute-names
> > output attribute-value
>
> This is what i posted does, in set-based fashion, to use a SQL term.
> What you indicated originally was more "cursor based".
Yes, I suppose you are right. I guess I'm just fixating on the nested
for-eachs, since you're collecting the (column name) attributes from
the source tree on each iteration, aren't you? That just feels
expensive to me. Maybe it's not.
> >Where list-of-attribute names is generated once in advance. Then
> >it would be just O(n) where n is the number of rows.
>
> Sure, just pre-select them into a variable, and use that in the
> inner loop.
OK, that's more like what I was thinking of. In fact, I tried to do
that and failed. (I think your next post gives an implementation.)
--
Paul.
w http://logicsquad.net/
h http://paul.hoadley.name/
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