Re: vacuuming and reindexing - Mailing list pgsql-admin

From Diogenes Caraballo
Subject Re: vacuuming and reindexing
Date
Msg-id c82353130903210631x71e1e8a0u65d2684ce2d48292@mail.gmail.com
Whole thread Raw
In response to vacuuming and reindexing  ("Tena Sakai" <tsakai@gallo.ucsf.edu>)
List pgsql-admin
do you also update rows of that table?

because that action delete old one's and insert new one's..

if you are just inserting rows and not updating or deleting, i think is correct your point.


Regards,
--
"Sin desafíos la vida es una rutina, una lenta agonía"

     Diógenes Caraballo


On Fri, Mar 20, 2009 at 18:03, Tena Sakai <tsakai@gallo.ucsf.edu> wrote:

Hi Everybody,

I have a table that I add rows every evening.
A rule I have for this table is that no row
ever gets deleted.  It has 600+ million rows.

The last time I did it, it took nearly 4 hours
to vacuum and 13 hours 40 minutes to reindex.

My rudimental understanding of vacuuming is
that when the rows get "deleted" it is only
marked as "deleted" but the data is left alone
until the act of vacuuming takes place.  The
vacuuming really gets rid of rows and pushes
the data in such the way there is no "hole."
And therefore after vacuuming, it is necessary
to reindex (and analyze) the table.

Is this a correct understanding?

If it is (and as new rows get added new indexes
are also built for the new rows), the fact that
there is no deletion means there is no necessity
for vacuuming this particular table?

I appreciate any thoughts on this matter.

Regards,

Tena Sakai
tsakai@gallo.ucsf.edu




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