Re: Database Link Question (For Guru)!

That's a simple one.
AFAIK, doing joins will kill your network, as all of the remote data is sent over, the join is done locally. Think of introducing views on the remote site - these will be processed remote, and the result set (which will be smaller) sent over the network.

bottom line: it depends on the type of query (but joins are quite common, aren't they?)

hth, frank

Marc Billiet wrote:
>
> You can see what is executed where by investigating the execution plan. As
> you can see, the following statement is entirely executed on the remote
> database.
>
> SQL> set autotrace trace
> SQL> l
> 1 select count(*) from delivery_at_dl_dev1
> 2*
> SQL> /
>
> Execution Plan
> ----------------------------------------------------------
> 0 SELECT STATEMENT (REMOTE) Optimizer=CHOOSE (Cost=32 Card=334
> 2)
>
> 1 0 SORT (AGGREGATE)
> 2 1 TABLE ACCESS (FULL) OF 'DELIVERY' (Cost=32 Card=3342)
> D021.WOR
> LD
>
> Marc
>
> japs1_at_my-deja.com wrote in message <8nsc3b$j6v$1_at_nnrp1.deja.com>...
> >Edward,
> >
> >Thanks for the reply.
> >
> >Can you (or anyone else) be more specific about which processor would
> >be doing the work.
> >
> >eg. if just querying Db2 tables for example from Db1, is it the Db1
> >server's processor that is used, or Db2's to execute the query.
> >
> >Thanks again,
> >
> >Paul.
> >
> >----------------------------------
> >
> >In article <8nr0d9$2rum$1_at_josh.sovintel.ru>,
> > "Edward" <eshevtsov_at_flagship.ru> wrote:
> >> Hello japs1.
> >>
> >> I'm not a guru, but I'll try ;-)
> >>
> >> skip...
> >>
> >> >The question I have is, where does the loading occur when a query is
> >> >executed from Db1 on Db2.
> >>
> >> I think it depends on type of your queries.
> >> If your queries are remotely (involve only Db2's tables) the most
 impact
> >> will be on Db2
> >> If you have distributed queries (on both Db1's and db2's tables) the
 loading
> >> depends on the nature of your queries
> >>
> >>
> >
> >
> >Sent via Deja.com http://www.deja.com/
> >Before you buy.
Received on Thu Aug 24 2000 - 07:09:08 CDT