Re: Sybase vs Oracle - which is better?

RobertSimmons wrote:
>
> Yassir Khogaly wrote:
> >
> > Sybase has only one type of backup, which requires the database to be up and
> > running. This is called online or Hot backup.
>
> This is not true. Sybase also allows you use file systems for devices.
> Therefore, the devices could be backed up just like any other file. I
> also beleive there are plenty of backup utilities that do partition
> image backups. Obviuosly the sybase server would need to be down while
> doing either of these.
>

If you put the database (not server) in "read only mode", you are effectively doing a cold backup. The Sybase engine and backupserver has to be up to do a backup but the database can be offline or even the server put in single user mode. Doing recoveries from the physical data device files is possible but not supported or guaranteed by Sybase. There are many variables that need to be taken into account when doing this.

> >
> > If the system crashes sybase database can be recovered from the backups (if
> > they were completed successfully) or from the database(dump).
> >
> Wouldn't Oracle would also need to be recoved from a successful backup
> of some type?
>
> > I've been in some situations were Controller on which the boot disk is
> > crashed, and although the boot disk was mirrored, the system was down.
> Sounds like your UNIX admins don't know how to swap disks.
>
> > Because Sybase claims to write the committed transaction directly to Row
> > Devices without OS interference ...? which does not make any sense... > anyway
>
> Using raw partitions allows Sybase to write directly to disk to avoid
> the latency the probably would be introduced by the OS holding data in a
> cache while reporting to Sybase that the data has been written to disk
> when, in fact, it has not.
>
> > Sybase engine did not complete writing the database dump, also the backups
> > were not complete, and hence could Not be used..!
> >
> This doesn't make much sense. How many programs could overcome a
> complete controller failure?
>
> > This happened here in the UK. in an installation adopted by Sybase UK.
>
> Sh*t happens.
>
> Robert
  Received on Sun Nov 29 1998 - 00:00:00 CST