Homework answers / question archive / Customer Management System The Customer Management System of an eCommerce application has the following relational schema: Customer (c-id, name, date-of-birth, income, street, thana, district, type) purchase (c-id, p-id, date, shop, quantity) product (p-id, pname, specification) Total customers are 80000 and the size of the customer relation is 8000 blocks

Customer Management System The Customer Management System of an eCommerce application has the following relational schema: Customer (c-id, name, date-of-birth, income, street, thana, district, type) purchase (c-id, p-id, date, shop, quantity) product (p-id, pname, specification) Total customers are 80000 and the size of the customer relation is 8000 blocks

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Customer Management System

The Customer Management System of an eCommerce application has the following relational schema:

Customer (c-id, name, date-of-birth, income, street, thana, district, type)

purchase (c-id, p-id, date, shop, quantity)

product (p-id, pname, specification)

Total customers are 80000 and the size of the customer relation is 8000 blocks. Total

purchase records are 240000 and the size of the purchase relation is 2400 blocks. The time

to transfer 1 block is 0.4ms and the average seek time in the disk is 8ms.

 

Q4. (a) Find the worst-case query processing cost using the block nested loop

join algorithm to process the following SQL with memory size 2 blocks.

SELECT * FROM customer c, purchase p WHERE c.c-id = p.c-id

(b) Explain the case if you increase the memory size to 2401 blocks.

 

 

 

Q5. (a) Write the query expression tree for the Algebra given below:

?c-id, name((?district= 'Bogra'(customer)) ? purchase) ? product)

(b) Explain the query expression tree.