Refer to the following ERD CUSTOMER Customer ID Cust Name Cust Address Holds CAR
ID: 3600628 • Letter: R
Question
Refer to the following ERD CUSTOMER Customer ID Cust Name Cust Address Holds CARD ACCOUNT MERCHANT Merch ID Merch Addr Account ID Card Type Card Type- dl DEBIT CARD CREDIT CARD CHARGES Charge Date Charge Time Bank No Cur Bal Let's make the following assumptions: .There are 12,500,000 . These customers have altogether 40,000,000 card accounts, 80% are credit card while 20% are debit card customers accounts .There are 3,200,000 merchants On average, there are 30 charges per merchant, per day. The range is very large. Customers are making on average, 2,000,000 requests per day to view their accounts and balances Merchants are making on average, 5,000,000 requests per day to view the transactions they have submitted to the bank. What opportunities for denormalization can you identify?Explanation / Answer
Sometimes normalisation is also not good for databases . Most of the times in OLAP transactions denormalisation gives best results and again that too based on the organisation needs only.
Another thing is while writing programs for front end applications programmers feel great difficulty to include statements for normalised database because it requires many joins queries retrieval queries etc. But with the denormalised database it will be easy to write programs for developers and pull the reports from that denormalised database. So this will be the one of the opputunity I feel for the denormalisation i..e to pull the records of the cards and customers information easily from the front end by denormalising the above database.