On Fri, 2005-07-29 at 09:41 +0530, Gnanavel S wrote:
> > Joined: > > test=> explain analyze > test-> SELECT cli_name,order.* > test-> FROM order > test-> JOIN client ON (ord_client = cli_code) > test-> WHERE ord_batch='343B' AND > ord_id='12-645'; > > where is the cli_code condition in the above query?
I don't understand the question. ord_client is the client code, and cli_code is the client code, for their respective tables. batch/id is unique, so there is only one record from order, and only one client to associate.
Clearer?
ok.
Reason might be comparing with a literal value (previous case) is cheaper than comparing with column(as it has to be evaluated). But with the previous case getting and assigning the cli_code in the application and executing in db will be time consuming as it includes IPC cost.
