Question

"Database design" is the second phase in the database life cycle. This phase focuses on the design of the database model that will support an organisation’s operations and objectives. Explain key activities along with relevant examples in the context of designing a database to support the medical practice’s patient appointments system.  

Based on the definition of a transaction as “a logical unit of work that must be entirely completed or aborted; no intermediate states are accepted”, use a specific example to demonstrate why no intermediate states are accepted.

Answer 1

Sol:

Database design.

We know that designing is nothing but modeling . So Database design is nothing but making an effective database that will fulfill the requirements of the user and system. lets analyse the steps and activities of designing a database to support the medical practice’s patient appointments system.  

* For a patient appointments system , the database are needed to store the details of the patients.

* The necessory datas of hospital need to be stored in DBMS

* Needed to store the payments details.

The above mentioned are some activities

All the datas are stored in tables hence it is very essential to create separate tables for the project. Here in the medical practice’s patient appointments system the main objective is to take the details from the patients and stored it in database and output them the list .

Lets take an example of doctor availability checking - for that first only we need to create a table of doctors , when the patient select a specific doctor for consulting , the patient data should stored in the queue/table of that doctor.

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There is no intermediate state in the transaction . lets take an example of online payment and analyse the statement.

We know that a successfull transaction will result the change of the state of database . When we trasfer our money to another account same time the money in our account debited and it should add in the other person account . The process should be completed fully or it should cancel initially itself . else it will create a inconsistancy in the state.

Hence for avoiding such problems there is no intermediate state accepted in transaction .