Re: [PORTS] vacuum takes too long - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [PORTS] vacuum takes too long
Date
Msg-id 199901070050.TAA20530@candle.pha.pa.us
Whole thread Raw
In response to Re: [PORTS] vacuum takes too long  (David Wetzel <dave@turbocat.de>)
Responses Re: [HACKERS] Re: [PORTS] vacuum takes too long
List pgsql-hackers
> > From: Bruce Momjian <maillist@candle.pha.pa.us>
>
> > > insert a few row in a table (>50000) and do
> > > delete from mytable;
> > > vacuum verbose  analyze;
> > >
> > > Why is this that slow?
> >
> > Analyze checks every column in every row.
>
> even if you only type "vacuum verbose" it takes _very_ long.
>
> I deleted _all_ records with "delete from mytable;" before.
> A drop and a new create is faster. But what is when you delete (maybe
> 100000) rows but keep 100 in the table?
>
> I use 6.4.2 on NetBSD/i486 (that box makes gets 12MBytes/sec via the
> filesystem out of the drives)

Not sure what to say.  Vacuum does take a while, and it is often faster
to drop and recreate.

--
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

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