Re: [ADMIN] dump/restore needed when switching from 32bit to 64bit

[Dirk Lutzebäck <lutzeb@xxxxxxxxxx>]

Thanks Tom,

we now stay with 32bit to allow backward compatibilty with XEON which is needed as a fail-over system.

The question is which gcc cflags are best used with XEON and Opteron to achieve fail-over compatibility. This is what we used for postgresql 8.0.3:

XEON, RHEL 3.0 AS:
    CFLAGS = "-mcpu=pentium4 -march=pentium4"

Opteron 875, RHEL 3.0 AS,  gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-42):
    CFLAGS = "-Acpu=x86_64 -Amachine=x86_64"

Do we still need a dump/restore with this config?

Regards,

Dirk


Tom Lane wrote:

=?ISO-8859-1?Q?Dirk_Lutzeb=E4ck?= <lutzeb@xxxxxxxxxx> writes:
  

when have a 8.0.3 database running on a XEON machine. We want to replace 
it with an Opteron where postgresql is to be compiled with 64bit. Do we 
need a dump/restore or can we just start the db with the new compilation?
    

I'd bet you need a dump/restore --- MAXALIGN is most likely different
on the two platforms.  If it isn't, then maybe you could get away with
this, but it's definitely risky.

			regards, tom lane