Re: Large table update/vacuum PLEASE HELP! - Mailing list pgsql-general

From Tom Lane
Subject Re: Large table update/vacuum PLEASE HELP!
Date
Msg-id 1935.1019000288@sss.pgh.pa.us
Whole thread Raw
In response to Re: Large table update/vacuum PLEASE HELP!  (Dmitry Tkach <dmitry@openratings.com>)
List pgsql-general
Dmitry Tkach <dmitry@openratings.com> writes:
> But in general, if I put this database into production, I am going to
> routinely update about 10-15% of all the rows in that table every
> month... How bad it is?
>  Am I going to need a 'vacuum full' after every update? Or how often
> would it be practical to do that?

I wouldn't recommend a VACUUM FULL at all.  Just do plain VACUUMs on
a regular basis, and accept the 10% or so storage overhead.

VACUUM FULL is good for the sort of situation where you've updated all
or most of the rows at one time, and now you have a factor-of-2 storage
overhead; you need to physically compact the table.  But the price of
doing that is high enough that I wouldn't do it to save 10-15%.

            regards, tom lane

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