Re: dataguard

• Veres Lajos <vlajos_at_ludens.elte.hu> wrote:

> > What is size of your application? How many tables? volume. Depending, Oracle Streams may also be an option.
>
> Rman dump is about 3 G.
> Exp dump~ 1.8 G.
> We have 70-80 tables.
> Most of selects uses a single (products) table.
> If we could spread the queries against that table that would be a big
> gain too.

80 tables are not that difficult to replicate in a Streams environment. You could also spread the queries using the service names to point to the second instance. You databases are now Read/Write on both end.
>
> > But DML redirect to master only may need some work, if application cannot support that. (or use specific service names for application? )
>
> I think we can modify our application. This isnt a big issue.

It means you should have either

    (1) Both Read/Write instances
    (2) Read Only instance and One Read/Write (master)

> There is any way to apply the logs continually and meantime read from the
> standby database?
> Or this operations exclude the other?

You could also use the new flashback feature on 10gR2 Data Guard to take an instance up for read/write. But you cannot have both logs applied, and have the standby database opened.

Sam Chakkanat
America's C-Bench
http://www.cbenchusa.com

> >
> > ---- Veres Lajos <vlajos_at_ludens.elte.hu> wrote:
> >> Hello,
> >>
> >> (I never used dataguard before. Sorry for my lame questions.)
> >>
> >> Is it possible to syncronize nearly on-line and use the "backup" database
> >> as a select-only node with loadbalancing?
> >> Our system is 99% read-only. Dataguard seems to be good for
> >> redundancy/failsafe, but it would be great if we could use the "backup"
> >> machines CPU too.
> >>
> >> TNS can spreads SELECTs between the two nodes, and redirect DMLs to
> >> only the master?
> >> (Isnt a big problem if TNS cant, then the applications DB layer
> >> should do it.)
> >>
> >> Other solution could be a Master->Slave replication, but I think it
> >> wont be as solid.
> >>
> >> Exists any other Oracle solution for "cumulate computers power"?
> >> I heard about RAC, but seems a bit expensive for us. (Shared storage)
> >>
> >> Any comment, experience, suggestion, (rtfm keyword) would be really
> >> appreciated.
> >>
> >> Thanks.
> >> --
> >> Veres Lajos
> >> vlajos_at_ludens.elte.hu
> >> +36 20 438 5909
> >> --
> >> http://www.freelists.org/webpage/oracle-l
> >>
> >>
> >
> >
>
> --
> Veres Lajos
> vlajos_at_ludens.elte.hu
> +36 20 438 5909
> --
> http://www.freelists.org/webpage/oracle-l
>
>

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