Thread

Re: [HACKERS] database size

Marc G. Fournier <scrappy@hub.org> — 1998-01-07T00:18:19Z

On Tue, 6 Jan 1998, Tony Rios wrote:

> At 06:09 PM 1/6/98 -0500, Shiby Thomas wrote:
> 
> >Hi,
> 
> >
> 
> >I created a table with two columns of type int, and loaded about 300 K records
> 
> >in it. So, the total size of the table is approx. that of 600 K integers,
> 
> >roughly 2.4 MB.
> 
> >But, the file corresponding to the table in pgsql/data/base directory
> 
> >has a size of 19 MB. I was wondering if I have done something wrong in
> 
> >the installation or usage, or is it the normal behavior ?
> 
> >
> 
> 
> Just wondering.. did you happen to do an INSERT into the database,
> 
> then delete some rows.. say 19megs worth, then re-add...  From what I've
> 
> seen msql db's will always be at least the size of the largest you've ever
> 
> had the database before.  It will over time, overrite existing deleted
> 
> records, but it keeps the data still in there, just sets a delete flag.
> 
> 
> If you really need to cut the size down, I've had to delete the database
> 
> completely, then create another table from scratch.  Not sure if there
> 
> is a 'purge' type function available, but you have to be careful that
> 
> nobody is accessing the db at that time, since it's very sensitive at
> 
> that time.

	vacuum will clean out the deleted records and truncate the table...has
been so since v6.1, I believe...


Marc G. Fournier                                
Systems Administrator @ hub.org 
primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org