Re: Covering Indexes

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От Aidan Van Dyk
Тема Re: Covering Indexes
Дата
Msg-id CAC_2qU-GbSKjY3B2Bsrh9jY6JctPBy3pFYw-cQ+rF8TNB+J7xg@mail.gmail.com
обсуждение исходный текст
Ответ на Re: Covering Indexes  (Alvaro Herrera <alvherre@commandprompt.com>)
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On Thu, Jun 28, 2012 at 12:12 PM, Alvaro Herrera
<alvherre@commandprompt.com> wrote:

> The other question is whether such an index would prevent an update from
> being HOT when the non-indexed values are touched.  That could be a
> significant difference.

I don't see Index-Only-Scans being something that will be used in
"high churn" tables.

So as long as the value of these "covering/included" fields is tied to
index-only scans, maybe it isn't a problem?

Of course, we have have a hard time convincing people that the  "index
only" scans they want can't be "index only" because heap pages aren't
"all visible"...

a.

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Aidan Van Dyk                                             Create like a god,
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http://www.highrise.ca/                                   work like a slave.

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