Follow up to this question:
There's one question left - perhaps somebody from SAP/Sybase can answer it: Why this option has such a so big impact to the performance with proxy tables? If I do the SELECT without proxy-tables (tables in the same database) there are no performance issue!
You can reproduce the behavior with the sample-db and the following SELECT. The customer-table must be a proxy table. Then you should play around with the optimization-goal option ("First-row" = slow, "All-rows" = fast).
In my case the customer-table has approx. 48000 rows, the salesorders has approx. 150 records.
select salesorders.id, customers.surname from salesorders, customers where salesorders.customerid = Customers.ID order by salesorders.id;
If you change the order to "order by salesorders.id, customers.surname", it's fast, even with "first-row".
I think there's a bug :-)
I have not taken the time to repro the issue (a sql script to repro the issue would have been nice) but my 'shot in the dark' guess is that:
Looking at the plans for each query will verify (or show otherwise) why you are getting fast vs slow query execution.
answered 18 Dec '13, 09:20