Search Postgresql Archives

Re: When does CLUSTER occur?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 11/29/2012 12:20 PM, Jeff Janes wrote:

It would maintain an imperfect clustering, but still much better than
current behavior.

I thought about that, too. The "imperfect clustering" made me erase everything I'd written. If the clustering is imperfect, it's not really clustering. It would mean less random reads to restart the seek chain though, so it would be a perceptible gain. But it's still not real clustering until the order is maintained indefinitely.

So far as I know, that simply can't be done with MVCC. Especially on an insert-only table that's clustered on a column unrelated to insert order.

--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604
312-444-8534
sthomas@xxxxxxxxxxxxxxxx

______________________________________________

See http://www.peak6.com/email_disclaimer/ for terms and conditions related to this email


--
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux