Joining two huge tables

Question

Hi
I have two tables PRODUCT , ORDERS and table having 20 million ,50 million rows.How to join two tables i mean join 20 million with 50 million and returns 50 million rows ?Please anyone what is the best way
to achive this?
SQL> desc orders;
Name Null? Type
ORDER_ID NOT NULL NUMBER(12)
ORDER_DATE NOT NULL TIMESTAMP(6) WITH LOCAL TIME
ZONE
ORDER_MODE VARCHAR2(8)
CUSTOMER_ID NOT NULL NUMBER(6)
ORDER_STATUS NUMBER(2)
ORDER_TOTAL NUMBER(8,2)
SALES_REP_ID NUMBER(6)
PROMOTION_ID NUMBER(6)
SQL> desc products;
Name Null? Type
PROD_ID NOT NULL NUMBER(6)
PROD_NAME NOT NULL VARCHAR2(50)
PROD_DESC NOT NULL VARCHAR2(4000)
PROD_SUBCATEGORY NOT NULL VARCHAR2(50)
PROD_SUBCAT_DESC NOT NULL VARCHAR2(2000)
PROD_CATEGORY NOT NULL VARCHAR2(50)
PROD_CAT_DESC NOT NULL VARCHAR2(2000)
PROD_WEIGHT_CLASS NUMBER(2)
PROD_UNIT_OF_MEASURE VARCHAR2(20)
PROD_PACK_SIZE VARCHAR2(30)
SUPPLIER_ID NUMBER(6)
PROD_STATUS NOT NULL VARCHAR2(20)
PROD_LIST_PRICE NOT NULL NUMBER(8,2)
PROD_MIN_PRICE NOT NULL NUMBER(8,2)
Thanks inadvance
Mohan

Answer 1

When you ask "what is the best way to join these" do you mean (1) how to get the best query plan or (2) how to write the SQL syntax, or (3) how to design the tables' schemas to reflect the right relationship?
I'm assuming #3 because that looks wrong to me. Without really knowing your app, it looks to me like these 2 tables have a M:M relationship (a single product can be associated with many orders, and a single order can be associated with many products). In that case, you should not have the order_id in the products table. You should instead have a 3rd table that maps an order_id to a product_id (it has just those 2 columns).
Did I guess the right question?
Tom Best