Re: Slow count(*) again...

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От Jesper Krogh
Тема Re: Slow count(*) again...
Дата
Msg-id 4CB5F394.6090909@krogh.cc
обсуждение исходный текст
Ответ на Re: Slow count(*) again...  (Robert Haas <robertmhaas@gmail.com>)
Ответы Re: Slow count(*) again...  (Robert Haas <robertmhaas@gmail.com>)
Список pgsql-performance
On 2010-10-13 15:28, Robert Haas wrote:
> On Wed, Oct 13, 2010 at 6:16 AM, Neil Whelchel<neil.whelchel@gmail.com>  wrote:
>
>> I might go as far as to rattle the cage of the developers to see if it makes
>> any sense to add some column oriented storage capability to Postgres. That
>> would be the hot ticket to be able to specify an attribute on a column so that
>> the back end could shadow or store a column in a column oriented table so
>> aggregate functions could work on them with good efficiency, or is that an
>> INDEX?
>>
> I'd love to work on that, but without funding it's tough to find the
> time.  It's a big project.
>
Is it hugely different from just getting the visibillity map suitable
for doing index-only scans and extracting values from the index
directly as Heikki has explained?

That would essentially do a column oriented table (the index itself)
of a specific columns (or column set).

... still a huge task though.

--
Jesper

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