Thanks for the answer, Mark. Now I start to get it.
"Mark A" <nobody_at_nowhere.com> wrote in message
news:vvydnaeHqO1l6pbfRVn-rA_at_comcast.com...
> "Valentin Minzatu" <v.a.l.e.n.t.i.n.m.i.n.z.a.t.u_at_y_a_h_o_o.c_o_m> wrote
in
> message news:tKWdnTrD5KFGxpbfRVn-sg_at_rogers.com...
> > I still cannot recollect which IBM document I've seen where it was
stated
> > that DB2's HA feature does not replicate DDLs or some of them, but I
will
> > get back once I find it. Consider this one closed for now.
> >
>
> There are several flavors of HA in DB2, none of them the same as RAC.
>
> - HACMP cluster - shared disk
> - HADR - all SQL replicated via logs
> - Q Replication - only DML replicated via MQ Seies
> - Data Partitioning Feature (DPF) - Not applicable
>
> HADR does do all SQL (including DDL) on both nodes, anything that hits the
> logs.
>
> > Per my understanding: DB2 partitions the data at the cluster level (must
> you
> > have a cluster, parallel server?), therefore each node has its own data
> and
> > when the query is submitted, one node acts as a dispatcher while the
> others
> > execute it and then the results are merged in memory. Oracle allows for
> this
> > as well, but it does not impose it as a limit. One could easily execute
> the
> > same query in a serial manner (i.e. one single server process retrieves
> all
> > the data querying each partition). The advantage is that if one of the
> nodes
> > go down you do not need to repartition the table or move data around at
> all.
> > It is already available as it is shared by all nodes. - please correct
me
> if
> > i am wrong - I would also like to know if DB2 has the ability to
exchange
> > partitions without taking the table/partition offline.
> >
> This would be for DPF. HACMP uses shared disk. Q-Replicaiton and HADR also
> can use shared disk (but only for the logs or the Q Replciation que).
>
>
Received on Thu Feb 10 2005 - 21:37:19 CST
