Re: Move database from Sun Solarias 5.8 to HPUX 11.11 pa-64

"DK" <dakight_at_bellsouth.net> wrote in message news:5ZMBc.2754$lp1.1595_at_bignews5.bellsouth.net...
> Correct me if I'm wrong but I thought both sun and hp used the same
> "Endian". Both file systems will be using veritas file system.
>
> --
> DAVID KIGHT
> "anacedent" <anacedent_at_hotmail.com> wrote in message
> news:NOMBc.22405$8r5.14319_at_fed1read03...
> > DK wrote:
> >
> > > OK. Can someone please explain why it won't work.
> > >
> > different filesystems
> > different "Endian"; big-Endian vs. Little Endian
>

In 10G this might work after a conversion routine. It might work, but it might subtly fail. Oracle is written in C and for structures you can specify different byte alignment for structures etc. When Oracle reads a block off the disk it reads it unchanged into memory. Now if you go from a system where they had even byte alignment to something that had a different byte alignment (typically an OS change) then sometimes things may be out of alignment and at best the system crashes and at worst you corrupt your data.

It has nothing to do with the Veritas File system or not. It does have to do with endian differences and what compiler option is used when the source code was compiled. Oracle may or may not use the same byte alignment from platform to platform; they don't publish this information.

How do I know this? Once upon a time a long time ago I worked for a company that supported Oracle on Netware. (and HPUX and Windows NT) Our application was migrating from 7.3.4 to 8.1.6 and on Netware we had to create a special migration tool. The migration tool had to export the complete database, drop the database, build a new database and reimport the database. Oracle was even willing to lend our customers SCSI drives to do the conversion. We didn't really want to do all this work - our customers did not have IT shops so we had to automate this process as much as possible. We pushed back as to why? The reason was Oracle 7.3.4 on Netware was compiled with no byte alignment and Oracle 8.+ on Netware was compiled with a different byte alignment. (I forget what the byte alignment was other than it was different.) So Oracle 8.+ on Netware couldn't read the old stuff and the only way to do the conversion was good old export, build new, import.

No byte alignment cause all sorts of problems, but we won't go into that. Jim Received on Tue Jun 22 2004 - 00:06:52 CDT