Hi,
I've been asked to do sql join strategies testing times to retrieve data.
I am doing a simple hash join of two tables
e.g.
Select /*ordered use_hash (customer) */ cust_lname
from customers, orders
Where customers.cust_id = <=500
AND customer.Order_id = orders.order_id
there are 2000 records in the customer table, and i expected 500 results....not the 1500 i got!
I would expect this large number of records if i was accessing the orders table (it has 3500 records with cust_id replication)...but not from just accessing the customer table!
Please please help, i'm so lost
)
I've been asked to do sql join strategies testing times to retrieve data.
I am doing a simple hash join of two tables
e.g.
Select /*ordered use_hash (customer) */ cust_lname
from customers, orders
Where customers.cust_id = <=500
AND customer.Order_id = orders.order_id
there are 2000 records in the customer table, and i expected 500 results....not the 1500 i got!
I would expect this large number of records if i was accessing the orders table (it has 3500 records with cust_id replication)...but not from just accessing the customer table!
Please please help, i'm so lost
)
