Re: Slow count(*) again...

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От Robert Haas
Тема Re: Slow count(*) again...
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Msg-id AANLkTi=vwE5-Gh_JmGLV=PTpaNwthaoFHnwhEaV7OOoS@mail.gmail.com
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Ответ на Re: Slow count(*) again...  (Jesper Krogh <jesper@krogh.cc>)
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On Wed, Oct 13, 2010 at 1:59 PM, Jesper Krogh <jesper@krogh.cc> wrote:
> 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?]

I think that there's a lot more to a real column-oriented database
than index-only scans, although, of course, index-only scans are very
important.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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