Re: odd problem !

On Tue, 22 Mar 2005, Tom Lane wrote:

> Oleg Bartunov <oleg@sai.msu.su> writes:
>>> What PG version is this exactly?
>
>> REL8_0_STABLE, I believe. I posted another problem, now "cut and pasted".
>
> I've been able to duplicate this here.  What is happening is that the
> damage to ./t1 is being done when you start the postmaster in ./t2.
> It looks to me like the fundamental problem is that the t2 postmaster
> is replaying the WAL-logged CREATE DATABASE command from t1's xlog, and
> *that log entry contains an absolute path name*.  So the CREATE replay
> is wiping out t1's "test" database subdirectory.

I suspected this.
btw,is there any utility to see WAL log in human-readable format ?

>
> This isn't a problem in normal use of course, but it'd be a serious
> issue for someone engaging in WAL-shipping, if their backup postmaster
> were living at a different absolute path.  We probably need to think

right, this is normal situation if you backup to the same server.
Not sure how it's usefull, but still

> about whether we can make CREATE DATABASE log only relative paths.

any problem ?

>
> Log-shipping CREATE TABLESPACE commands is even more interesting :-(.
> Not sure how to deal with that.
>

in general case it's impossible. Just speculating, what if we have some
dedicated directory doing symbolical links there for all tablespaces ?


>             regards, tom lane
>
    Regards,        Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83