Re: [HACKERS] database size

Bruce Momjian <maillist@candle.pha.pa.us>

From: Bruce Momjian <maillist@candle.pha.pa.us>
To: scrappy@hub.org (The Hermit Hacker)
Cc: darrenk@insightdist.com, pgsql-hackers@postgreSQL.org, sthomas@cise.ufl.edu
Date: 1998-01-07T03:02:42Z
Lists: pgsql-hackers
> 
> On Tue, 6 Jan 1998, Darren King wrote:
> 
> > 48 bytes + each row header (on my aix box..._your_ mileage may vary)
> >  8 bytes + two int fields @ 4 bytes each
> >  4 bytes + pointer on page to tuple
> > -------- =
> > 60 bytes per tuple
> > 
> > 8192 / 60 give 136 tuples per page.
> > 
> > 300000 / 136 ... round up ... need 2206 pages which gives us ...
> > 
> > 2206 * 8192 = 18,071,532
> > 
> > So 19 MB is about right.  And this is the best to be done, unless
> > you can make do with int2s which would optimally shrink the table
> > size to 16,834,560 bytes.  Any nulls in there might add a few bytes
> > per offending row too, but other than that, this should be considered
> > normal postgresql behavior.
> 
> 	Bruce...this would be *great* to have in the FAQ!!  What we do need is
> a section of the User Manual dealing with computing resources required for
> a table, similar to this :)

Added to FAQ.

-- 
Bruce Momjian
maillist@candle.pha.pa.us