Re: reducing random_page_cost from 4 to 2 to force index scan

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От Jeff Janes
Тема Re: reducing random_page_cost from 4 to 2 to force index scan
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Msg-id BANLkTimw2xWYQ_Hz4vtLXx-2nZRjRfoMMw@mail.gmail.com
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Ответ на Re: reducing random_page_cost from 4 to 2 to force index scan  (Jesper Krogh <jesper@krogh.cc>)
Ответы Re: reducing random_page_cost from 4 to 2 to force index scan  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-performance
On Sun, May 15, 2011 at 9:49 PM, Jesper Krogh <jesper@krogh.cc> wrote:
>
> Ok, it may not work as well with index'es, since having 1% in cache may very
> well mean that 90% of all requested blocks are there.. for tables in should
> be more trivial.

Why would the index have a meaningful hot-spot unless the underlying
table had one as well?  (Of course the root block will be a hot-spot,
but certainly not 90% of all requests)

Cheers,

Jeff

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