Search Postgresql Archives

Re: Vacuum time degrading

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

 



Wes <wespvp@xxxxxxxxxxxx> writes:
> Ok, now I follow.  Taking the biggest indexes:

> The weekend before:
> INFO:  index "message_recipients_i_recip_date" now contains 393961361 row
> versions in 2435100 pages
> INFO:  index "message_recipients_i_message" now contains 393934394 row
> versions in 1499853 pages

> After reindex:
> INFO:  index "message_recipients_i_recip_date" now contains 401798357 row
> versions in 1765613 pages
> INFO:  index "message_recipients_i_message" now contains 401787237 row
> versions in 1322974 pages

OK, that's certainly not a factor-of-four difference in size, so I'm
now convinced you're right: bringing the index into physical order is
having a big impact on the runtime.

>From a development standpoint, that suggests a couple of TODO items:
* Look harder at whether VACUUM can scan the index in physical instead
  of logical order.
* See whether ordinary btree maintenance (ie page splits) can do
  anything to maintain/improve the physical ordering of the index.

			regards, tom lane

---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?

               http://archives.postgresql.org

[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