On 04/26/2016 05:55 AM, Rakesh Kumar wrote:
Pardon me if this has been discussed before.
I believe that PG back-end does not version index rows the way it does
the data rows. Assume that the app updates a row frequently (several
times in a second). For each update, PG will create a new version.
However I believe the primary key index pointing to that row will point
to only the first row and the back end has to work its way traversing
the list until it finds the appropriate row matching the xmin/xmax.
Does frequent vaccum take care of this by removing the dead rows and
hence reducing the commute.
Might want to take a look at:
http://www.postgresql.org/docs/9.5/interactive/indexam.html
--
Adrian Klaver
adrian.kla...@aklaver.com
--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
