Schemas Integration - Information Systems Reengineering, Integration and Normalization - page 275

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7.2 Case Study of Schemas Integration for RDBs

A bank has existing databases with different schemas: one for a Mortgage Loan
Customer, one for an Auto Loan Customer, one for Loan Contract, and one for an
Index Interest Rate. They are used by various applications in the bank. However,
there is a need to integrate them together for an international banking loan system.
The following are the four source schemas shown in Fig. 7.15 . In applying the algo-
rithm of our methodology, the relevant steps used in this case study are as follows:

loan contract#
begin_date
mature_date
ID#
loan-status

Customer
(mortgage
loan)

ID#
customer_name
date

loan contract

1

1

1

1

1

1

draw accure repaid balanced accumulate opened

1 1 (0,n) 1 n

n

Loan
interest
type

loan
history

account

Loan
drawdown

Loan
repayment

Loan
balance

loan contract #
drawdown_date
drawdown_amt

loan contract#
repayment_date
repayment

loan contract#
loan_bal_date
balance_ amt

account#

past loan #
past_loan _status

index
interest
type

index_interes_type

ID#
customer_name
date

Customer
(Auto loan)

1

has

n

index_interest_eff_date
index_interest_rate

index
interest
rate