Re: inheritance, and plans

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От Andrew Gierth
Тема Re: inheritance, and plans
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Msg-id 87eiyaqgbj.fsf@news-spur.riddles.org.uk
обсуждение исходный текст
Ответ на Re: inheritance, and plans  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: inheritance, and plans  (Tom Lane <tgl@sss.pgh.pa.us>)
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>>>>> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:

 [domain -> base type conversion interfering with optimization]

 Tom> You seem to be laboring under the delusion that this is
 Tom> considered a bug.

Of course it's a bug, or at least a missing feature - there is no
justification for putting performance deathtraps in the way of using
domains.

 Tom> It's a necessary semantic restriction, because the pushed-down
 Tom> expression could mean different things when applied to different
 Tom> data types.

How?

Type-dependent selection of operators has already been done as part of
parse analysis, no? And the domain -> base conversion is purely a
relabelling, no? So what semantic change is possible as a result?

--
Andrew (irc:RhodiumToad)


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