Re: Optimizing query on 2 servers?

If you check your explain plan, I think you will see that the join of table1 and table2 is taking place on server2. This means that a lot of rows must be sent over the network from server1 to server2 to be joined.

Try doing the join in a view on server1.

Lily Djuniarti wrote:

> I'm running a query with tables from 2 different servers. I have no problem
> accessing the tables because there are already links for the tables I need
> from, say, server2 to server1.
> The problem is, this query runs forever, so I'll appreciate any idea on how
> to optimize this query.
> The purpose is to retrieve customer data from server1 which are not on
> server2.
> I'm running the query on server2 where table3 is.
>
> SELECT
> FROM table1_at_server1, table2_at_server1
> WHERE ...
> AND table1_at_server1.id = table2_at_server1.id
> AND NOT EXISTS
> (Select 'X'
> from table3
> where
> table3.Customer like (table1_at_server1.first_name||'
> '||table1_at_server1.last_name))
>
> Thanks,
> LD
Received on Mon Jun 08 1998 - 11:44:55 CDT