I have looked in the archives for an answer to this and have not found
one as of yet, so I guess I'll pose the question here.
I'm working to set up a high-availability PostgreSQL server using WAL
shipping. Everything works very well with the set of scripts I have
developed and I'm down to my f
I have a question related to the WAL log. Our organization is looking at
using log-shipping to build a high-availability standby server. In our
tests the amount of WAL log data generated per minute is significant. On
our busiest database during a WAL archive test, eight 16 MB logs were
being used/a
y wrote:
> On Wed, May 16, 2007 at 10:28:29AM -0600, Keaton Adams wrote:
> > On most database systems I am used to, there is a physical log and
> > separate logical log. The physical log holds any ???before images??? of data
> > pages that have been modified since the la
aton
On Wed, 2007-05-16 at 11:51 -0500, Jim C. Nasby wrote:
> On Wed, May 16, 2007 at 10:49:04AM -0600, Keaton Adams wrote:
> > So, if I do set the checkpoint_segments parameter to 50, 75, or even 100
> > I will have a considerable number of WAL files in data/pg_xlog, but t
requent checkpoints would have added even more to the WAL
file overhead, is my understanding.)
So is there anything I can do to reduce the 34.8% overhead in WAL file
space when loading data? Do you see any glaring mistakes in the
calculations themselves, and would you agree with this overhead figur
When I issue an alter table . alter column command, the table
contents are copied from the old structure to the new, correct? So I
need 2x the table space available so the old and new tables can exist at
the same time? PostgreSQL doesn't use an in-place alter-table for these
types of changes,
After I sent my request I found the notes related to ALTER TABLE on page
1,331 of the 8.1 manual, so that helped to explain it. Your reply to my
post confirmed what I thought I was reading.
Thanks for the reply,
Keaton
On Tue, 2007-05-29 at 17:16 -0400, Tom Lane wrote:
> Keaton Ad
