Subject how to perform update with aggregate subselect ?
Author Andrew Guts
Hello all.

Help me please with this:

update table1
set total = (select sum(Quantity) from table2 where table2.CustomerID
= table1.CustomerID)

CustomerID is a foreign key for both tables, references to the same
table "Customers".
That operator hangs because table2 is large and engine uses natural
joins. How to work arround the problem?

Any help would be appreciated.

Thanks ahead.